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 A055066 Number of 7-covers of an unlabeled n-set. 8
 1, 7, 62, 664, 8609, 127415, 2004975, 31500927, 474504448, 6708348262, 88249739792, 1078567590128, 12269901302433, 130370516668917, 1298891291366245, 12182760243381355, 107979270564656625, 907568508195185203, 7256984238345563764, 55365443728411530716, 404091280028746802188 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Number of 7 X n binary matrices with at least one 1 in every column up to row and column permutations. - Andrew Howroyd, Feb 28 2023 LINKS Andrew Howroyd, Table of n, a(n) for n = 0..1000 Vladeta Jovovic, Binary matrices up to row and column permutations PROG (PARI) Vec(G(7, x)*(1-x) + O(x^40)) \\ G defined in A028657. - Andrew Howroyd, Feb 28 2023 CROSSREFS Column 7 of A055080. Cf. A005748, A002620, A005783, A005784, A005785, A005786. Sequence in context: A287481 A289212 A060005 * A216534 A167550 A304895 Adjacent sequences: A055063 A055064 A055065 * A055067 A055068 A055069 KEYWORD nonn AUTHOR Vladeta Jovovic, Jun 12 2000 EXTENSIONS a(0)=1 prepended by Alois P. Heinz, Aug 08 2022 Terms a(17) and beyond from Andrew Howroyd, Feb 28 2023 STATUS approved

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Last modified June 9 08:18 EDT 2023. Contains 363168 sequences. (Running on oeis4.)