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