This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A057966 #6 Feb 16 2025 08:32:43 %S A057966 1,156,15,14196,2730,140,984256,283920,29120,1050,57578976,22145760, %T A057966 3407040,245700,6951,2994106752,1439474400,295276800,31941000,1807260, %U A057966 42525,142719088512,82337935680,21112291200,3045042000,258438180 %N 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). %C A057966 Row sums give A046166. %H A057966 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MinimalCover.html">Minimal cover</a> %F A057966 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. %e A057966 [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. %Y A057966 Cf. A035347, A057669, A057963-A057965, A057967, A057968(unlabeled case). %K A057966 easy,nonn,tabl %O A057966 5,2 %A A057966 _Vladeta Jovovic_, Oct 17 2000