The tables currently have 9142 entries from 69 different contributors


last updated at 2017-03-24 12:25:00

Top Contributors

LJCR 4451
Jan de Heer and Steve Muir 2864
Colin Barker 321
Michael Dambmann 251
Tommaso Tanto 147
Terenzio Lazzarotto 144
Pio Leonardi 99
Flavio Perona 91
Anastasios Tampakis 89
Enzo Franzese 77
Kamal Fadlaoui 74
Jan de Heer 47
Alessandro Jurcovich 37
Rade Belic and Dragan Stojiljkovic 35
Rade Belic 34
Mathias Liesener 34
Barnabas Toth 28
Gerald Unger 27
Kinski and Genivaldo Pereira 26
Dietmar Pree 24
Andrei Ochmat 23
Vinicius Alves 22
Chaoying Dai, Ben Li and Michel Toulouse 22
Marco Meoli 20
Felix Rodriguez Martin 20
Luciano Rezende 18
Rade Belic and Jan de Heer 13
Adolf Muehl 13
Sveta Marjanovic 9
Aline Marie Menezes Wanderlei 8
Karsten Schölzel 6
W.h.mills and R.c.mullin 5
Roy Gourgi 5
W.h.mills 4
Sveta Marjanovic and Anastasios Tampakis 4
Jan de Heer and Rade Belic 4
Daryl Burns 4
Weberazevedo 2
Sveta Marjanovicandanastasios Tampakis 2
Steve Muir 2
Mario Pina 2
Kleszek 2
Iliya Bluskov 2
Guenther Schlegl 2
Francisco Carlos 2
Claus Friis 2
Bluskov and Hamalainen 2
W. H. Mills 1
Tung Le 1
Riccardo Bertolo and Jan de Heer 1
Riccardo Bertolo and Francesco Santisi 1
Rade Belic and Dietmar Pree 1
Nino Aspesi - Alessandro Jurcovich 1
Namyk Kemal Erdogan 1
Kinsky and Genivaldo Pereira 1
Karsten Scholzel 1
Jose Milan Vega 1
Jaera 1
Igor Lazebnik 1
Fausto Peirano 1
Dietmar Pree and Rade Belic 1
Dietmar Pree and Adolf Muehl 1
Daniel Morais 1
Chaoying Dai, Ben Li and Michel Toulouse, Reduced By Rade Belic 1
Alexandre Spaeth 1
Alessandro Jurcovich E Marco Meoli 1
Adolf Muehl and Dietmar Pree 1
A. Tampakis and A. Jurchovich 1
A. Betten, R. Laue and A. Wassermann 1





Overall there have been 65484 entries from 123 different contributors

All-time Contributors






LJCR 45851
Jan de Heer and Steve Muir 4988
Michael Dambmann 2239
Tommaso Tanto 1733
JCD Article 1632
Flavio Perona 1498
Rade Belic 1441
Terenzio Lazzarotto 1382
Rade Belic and Dragan Stojiljkovic 539
Colin Barker 457
Gerald Unger 343
Kinski and Genivaldo Pereira 278
Anastasios Tampakis 257
Felix Rodriguez Martin 244
Enzo Franzese 228
Barnabas Toth 228
Pio Leonardi 194
Dietmar Pree 155
Alessandro Jurcovich 144
Steve Muir 131
Aline Marie Menezes Wanderlei 131
Jan de Heer 129
Francisco Carlos 127
Marco Meoli 107
Luciano Rezende 100
Kamal Fadlaoui 89
Vinicius Alves 86
Sveta Marjanovic 68
Nino Aspesi 49
Mathias Liesener 47
Dietmar Pree and Rade Belic 41
Jose Milan Vega 40
Chaoying Dai, Ben Li and Michel Toulouse 39
Rade Belic and Jan de Heer 38
Jaera 38
Fausto Peirano 37
Gino Grazin and Rade Belic 31
Andrei Ochmat 31
Dragan Stojiljkovic 27
Jan de Heer and Rade Belic 19
Stefano de Martino 14
Roy Gourgi 14
Kleszek 12
Kabila 11
Flavio.perona 11
Igor Lazebnik 10
Weberazevedo 8
Sildemar Castro 8
Alessandro Jurcovich E Marco Meoli 8
Adolf Muehl 8
Weber Azevedo 7
Riccardo Bertolo 7
Daryl Burns 7
Mario Pina 6
Karsten Schölzel 6
W.h.mills and R.c.mullin 5
Sveta Marjanovic and Anastasios Tampakis 5
W.h.mills 4
Sveta Marjanovicandanastasios Tampakis 4
Riccardo Bertolo and Francesco Santisi 4
Rade Belic and Dietmar Pree 4
Leopio 4
Ivan Baptiste and Rade Belic 4
Michael Damb 3
Marco Meoli E Alessandro Jurcovich 3
Claus Friis 3
Tarullig / Aspesi 2
Riccardo Bertolo and Jan de Heer 2
Ricardo Ramalho 2
Paolo Ferlaino 2
Meoli Marco 2
Karsten Scholzel 2
Iliya Bluskov 2
Genivaldo Pereira 2
Bluskov and Hamalainen 2
Alessandro Jurcovich E Stefano de Martino 2
Adolf Muehl and Dietmar Pree 2
W. H. Mills 1
Tung Le 1
Tarullig/aspesi 1
Steve Muir, Improving One By Jan de Heer 1
Simple Construction: Doubled (50,9,3) and Deleted An Element 1
Simple Construction: Doubled (50,8,3) and Deleted An Element 1
Simple Construction: Doubled (50,8,2) and Deleted An Element 1
Simple Construction: Doubled (50,6,2) and Deleted An Element 1
Simple Construction: Doubled (50,11,3) and Deleted An Element 1
Simple Construction: Doubled (50,11,2) and Deleted An Element 1
Simple Construction: Doubled (50,10,4) and Deleted An Element 1
Simple Construction: Doubled (50,10,3) and Deleted An Element 1
Simple Construction: Doubled (50,10,2) and Deleted An Element 1
Quadrupling Construction 1
Qlatino 1
Peter Rosendahl 1
Paramini and Kabila and Aspesi 1
Nino Aspesi - Moreno Paramini 1
Nino Aspesi - Alessandro Jurcovich 1
Namyk Kemal Erdogan 1
Marjanovic Jurcovich Aspesi 1
Mario Tessuto 1
Marco Meoli Sveta Marjanovic 1
Marco Meoli Alessandro Jurcovich 1
Leo Pio 1
Lazzarotto Terenzio 1
Kinsky and Genivaldo Pereira 1
Jose Maria Milan 1
Jiang Yong Ming 1
Jan de Heer With Ininuga By Uros Boltin 1
Grzesiek 1
Gerasorte Online 1
Fernando Villanova 1
Edi8 1
Daniel Morais 1
Chaoying Dai, Ben Li and Michel Toulouse, Reduced By Rade Belic 1
Aspesi - Paramini - Tosi 1
Aspesi - Paramini - Marjanovic 1
Altopalato Bellariva 1
Alexandre Spaeth 1
Alessandro Jurcovich-sveta Marjanovic-marco Meoli 1
Alessandro Jurcovich - Nino Aspesi 1
Adolf Muehl and Rade Belic And Dietmar Pree 1
A. Tampakis and A. Jurchovich 1
A. Betten, R. Laue and A. Wassermann 1
42066 1

Methods used in current tables

Private tools 2568
Dynamic programming construction 1969
unknown1272
Simple construction 952
Multiple 628
Lex covering 258
Constructed 223
Simulated annealing 194
Dynamic programming covering 135
Simple construction: combined 79
Simple construction: multiple 70
Simple construction: induced 67
Lexicographic greedy covering 57
Wheel generator 47
Dynamic construction 40
Dynamic programming 37
Simple construction: deleted element 31
Tabu search 28
Private tool 28
Random greedy covering 23
Cyclic covering 23
Cyclic covering found by search program 20
Simple construction: added element to c(v-1,k-1,t) covering 18
Steiner quadruple system 16
Simple optimization 16
Sidorenko construction 15
Simple combine 11
Constructed using simulated annealing 11
Design is based on c (v - 1, k, t) = b - v 10
Cyclic construction 10
Simulated annealing covering 9
See paper by jrj abel et al. in discrete mathematics 307 (2007) 9
Cyclic covering found by a search program 9
Nurmela and ostergard simulated annealing cover 8
Nurmela-ostergard symmetric covering 7
Affine geometry covering 7
Induced 6
Exhaustive search 6
Covering provided by rade belic 6
Steiner triple system 5
Sidorenko method 5
See jct series a 49, 308-322 (1988) 5
Extraction/remainder 5
Colex greedy covering 5
Simple construction: added element to c(v,k-1,t) covering 4
See journal 4
Nurmela-ostergard simulated annealing covering design 4
Hanani construction (see canadian journal 4
Cyclic symmetry 4
Constructed using difference families 4
Wheel generator, based on jan de heer and steve muir work 3
Using ininuga, by uros boltin 3
Steiner system 3
Reverse engineering smaller systems 3
Projective plane 3
Modified cover32 routine by dietmar pree 3
Mills, jcta 13 (1972) pp. 55-78. 3
Mills, ars combinatoria, 8 (1979) pg. 247 3
Mills, ars combinatoria, 8 (1979) pg. 231 3
Mills, ars combinatoria 8 (1979) pp. 199-315 3
Found by a hill-climbing program 3
Cyclic steiner system 3
Covering provided by alex sidorenko (personal communication) 3
Covering found by a hill-climbing program 3
Constructed using dynamic programming 3
Using wheel generator 2
Steiner system (derived) 2
Simple method construction 2
Several methods (including sa) 2
Nurmela-ostergard simulated annealing covering 2
Jcd 1998, pp. 21-41 2
Hill-climb on cyclic orbits 2
Hill-climb on affine orbits 2
Covering provided by john cock (personal communication) 2
Covering provided by dietmar pree 2
Covering pairs by quads: mills, jcta 15:138-166, 1973. 2
Constructed using difference sets 2
Constructed by simulated annealing 2
Communicated by d. todorov, using pg(2,4) 2
Communicated by d. todorov, using pg(2,3) 2
Affine plane 2
Using td(6,16) and 6*modified c(18,6,2,2) 1
Using td(6,15) and 6*modified c(18,6,2,2) 1
Using resolvable c(72,4,2), see lamken, mullen and rees (jcd, 1997-1) 1
Using resolvable c(68,4,2), see lamken, mullen and rees (jcd, 1997-1) 1
Using rc(60,3,2) by lamken and mills (1993) 1
Using rc(54,3,2) 1
Using rc(45,3,2) 1
Using dietmar pree version 1
Using a resolvable c(54,6,2,2) 1
Using a 4−gdd 1
Using a (v,4,22*)-pbd and c(22,4,2) 1
Unusual methods 1
Tripling a resolvable c(25,5,2) 1
Td(7,13) and 7 * modified c(15,7,2) 1
Td(4,24) + 4*c(27,4,2) 1
Td(4,24) + 4 * c(26,4,2) 1
Td(4,23) + 4 * c(25,4,2) 1
Td(4,19) & 4 * c(21,4,2) 1
Td(4,18) + 4 * c(21,4,2) 1
Td(4,15) and 4 * modified c(18,4,2) 1
Td(4,12) & 4 * c(15,4,2) 1
Superfluous-element hill climb on a random greedy covering 1
Superfluous-element hill climb on a covering 1
Steiner system, taken 1
Simple multiple 1
Simple construction: doubled (50,8,3) and deleted an element 1
Simple construction: doubled (50,8,2) and deleted an element 1
Simple construction: doubled (50,11,2) and deleted an element 1
Simple construction: doubled (50,10,4) and deleted an element 1
Simple construction: doubled (50,10,2) and deleted an element 1
Simple construction: 1
See w h mills in congressus numerantium 10 (1974) pp563-581 1
See paper in journal 1
See j comb des , vol. 15, no. 6, pp. 511-533, 2007 1
See designs, codes and cryptography 17 (1999), 181-186 1
Reverse engineering 1
Replicate 4 columns 1
Quadrupling construction 1
Produced with covermaster (by john rawson), wheelgenerator (by anastasios tampakis) and private tools. 1
Private tools - assisted by wheel generator 1
Privat tools 1
Pritave tools 1
Normal methods 1
Mills, ars combinatoria, 8 (1979) pg. 270 1
Mills, ars combinatoria, 8 (1979) pg. 254 1
Mill, jcta 15 (1973) 138-166 1
Method 1
Marco meoli 1
Ininuga (by uros boltin) 1
Induced annealing 1
Group theory 1
From td(9,9) and 9*c(14,9,2,2,3) with 5 holes 1
From td(7,12) and 7*c(15,7,2,2,6) with 3 holes 1
From td(7,12) and 7*c(13,7,2,2,5) with 2 holes 1
From 57,8,2 1
From 1-flat on 42 numbers 1
Extraction 1
Ex 948 1
Ex 831 1
Ex 8 1
Ex 62 1
Ex 54 1
Ex 28 1
Ex 1821 1
Ex 16 1
Ex 15 1
Ex 1491 1
Ex 13 1
Ex 1257 1
Doubling resolvable c(25,5,2) 1
Doubling c(42,4,3) 1
Doubling c(36,4,3) 1
Doubling c(30,4,3) 1
Doubling c(18,4,3) 1
Cyclic symmetrical 1
Cyclic covering on z5*z7 1
Cyclic covering on z3*z17 with one point at infinity 1
Cyclic 1
Covering provided by konstantin katskov, found by exhaustive search 1
Covering produced by floyd l. oats, using a ranking and reduction process 1
Covering pairs by quints, mullin, jcmcc 2:133-146, 1987 1
Covering pairs by quints, mills & mullin, jcta 49:308-322, 1988 1
Covering found by rade belic 1
Covering found by john rawson 1
Covering 1
Construction combined 1
Communicated by d. todorov 1
Combinado 1
Chain rule (64,32,6)x(32,24,6) 1
Block-array construction (gordon, patashnik, petro and taylor) 1
Block covering 1
Based on work by chaoying dai, ben li and michel toulouse 1
Based on an improvement by dietmar pree 1