OFFSET
2,4
LINKS
Eric Weisstein's World of Mathematics, Proper covers
EXAMPLE
[0, 1], [0, 2, 5, 4, 2, 1], [0, 4, 19, 58, 113, 168, 193, 171, 119, 68, 29, 10, 3, 1], ...; There are 113 proper 5-covers of an unlabeled 4-set.
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Vladeta Jovovic, Jun 14 2000
STATUS
approved