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 A057966 Triangle T(n,k) of number of minimal 5-covers of a labeled n-set that cover k points of that set uniquely (k=5,..,n). 4
 1, 156, 15, 14196, 2730, 140, 984256, 283920, 29120, 1050, 57578976, 22145760, 3407040, 245700, 6951, 2994106752, 1439474400, 295276800, 31941000, 1807260, 42525, 142719088512, 82337935680, 21112291200, 3045042000, 258438180 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 5,2 COMMENTS Row sums give A046166. LINKS Eric Weisstein's World of Mathematics, Minimal cover FORMULA Number of minimal m-covers of a labeled n-set that cover k points of that set uniquely is C(n, k)*S(k, m)*(2^m-m-1)^(n-k), where S(k, m) are Stirling numbers of the second kind. EXAMPLE [1], [156, 15], [14196, 2730, 140], [984256, 283920, 29120, 1050], ...; there are 15 minimal 5-covers of a labeled 6-set that cover 6 points of that set uniquely. CROSSREFS Cf. A035347, A057669, A057963-A057965, A057967, A057968(unlabeled case). Sequence in context: A278432 A299829 A115466 * A247435 A299170 A112818 Adjacent sequences:  A057963 A057964 A057965 * A057967 A057968 A057969 KEYWORD easy,nonn,tabl AUTHOR Vladeta Jovovic, Oct 17 2000 STATUS approved

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Last modified July 24 03:01 EDT 2019. Contains 325290 sequences. (Running on oeis4.)