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 A005748 M5098 #22 Feb 28 2023 22:25:07 %S A005748 1,20,348,6093,108182,1890123,31500927,490890277,7086257602, %T A005748 94548676765,1167995082810,13406707973018,143598707530374, %U A005748 1441525802509250,13619352767824724,121574625625030584,1029031775725235400,8285521569322196569,63648858792893665714 %N A005748 Number of n-covers of an unlabeled 7-set. %C A005748 Number of n X 7 binary matrices with at least one 1 in every column up to row and column permutations. - _Andrew Howroyd_, Feb 28 2023 %D A005748 R. J. Clarke, Covering a set by subsets, Discrete Math., 81 (1990), 147-152. %D A005748 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005748 Andrew Howroyd, <a href="/A005748/b005748.txt">Table of n, a(n) for n = 1..1000</a> %H A005748 Vladeta Jovovic, <a href="/A005748/a005748.pdf">Binary matrices up to row and column permutations</a> %o A005748 (PARI) Vec(G(7, x) - G(6, x) + O(x^30)) \\ G defined in A028657. - _Andrew Howroyd_, Feb 28 2023 %Y A005748 A diagonal of A055080. %K A005748 nonn %O A005748 1,2 %A A005748 _N. J. A. Sloane_, _Simon Plouffe_ %E A005748 Corrected and extended by _Vladeta Jovovic_, Jun 13 2000 %E A005748 Terms a(17) and beyond from _Andrew Howroyd_, Feb 28 2023