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 A005771 M4856 #23 Feb 28 2023 22:25:02 %S A005771 1,12,103,736,4571,25326,127415,588687,2518997,10053739,37656707, %T A005771 133084998,445949359,1422934989,4340110439,12697803333,35744330644, %U A005771 97081519369,255032046536,649459943602,1606518048420,3867119228081,9073566868140,20783186834063 %N A005771 Number of n-covers of an unlabeled 5-set. %C A005771 Number of n X 5 binary matrices with at least one 1 in every column up to row and column permutations. - _Andrew Howroyd_, Feb 28 2023 %D A005771 R. J. Clarke, Covering a set by subsets, Discrete Math., 81 (1990), 147-152. %D A005771 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005771 Andrew Howroyd, <a href="/A005771/b005771.txt">Table of n, a(n) for n = 1..1000</a> %H A005771 Vladeta Jovovic, <a href="/A005748/a005748.pdf">Binary matrices up to row and column permutations</a> %F A005771 a(n) = A052264(n) - A006148(n). - _Andrew Howroyd_, Feb 28 2023 %o A005771 (PARI) Vec(G(5, x) - G(4, x) + O(x^40)) \\ G defined in A028657. - _Andrew Howroyd_, Feb 28 2023 %Y A005771 A diagonal of A055080. %Y A005771 First differences give A055083. %Y A005771 Cf. A006148, A052264. %K A005771 nonn %O A005771 1,2 %A A005771 _N. J. A. Sloane_, _Simon Plouffe_ %E A005771 More terms from _Vladeta Jovovic_, Jun 13 2000 %E A005771 Terms a(21) and beyond from _Andrew Howroyd_, Feb 28 2023