cp's OEIS Frontend

A331655 Number of binary matrices with n distinct columns and any number of distinct nonzero rows with 4 ones in every column and rows in decreasing lexicographic order.

%I A331655 #5 Jan 25 2020 02:12:27
%S A331655 1,0,0,1,272,64453,23553340,13241130441,11008118941631,
%T A331655 13027230343637042,21234181599255320655,46357847997267210103060,
%U A331655 132373322228662190671151849,484443861947038578745971380703,2232754658868099948336222687731941,12763566506391999019612414249332466653
%N A331655 Number of binary matrices with n distinct columns and any number of distinct nonzero rows with 4 ones in every column and rows in decreasing lexicographic order.
%C A331655 The condition that the rows be in decreasing order is equivalent to considering nonequivalent matrices with distinct rows up to permutation of rows.
%H A331655 Andrew Howroyd, <a href="/A331655/b331655.txt">Table of n, a(n) for n = 0..50</a>
%F A331655 a(n) = Sum_{k=0..n} Stirling1(n,k)*A188446(k).
%e A331655 The a(3) = 1 matrix is:
%e A331655   [1 1 1]
%e A331655   [1 1 0]
%e A331655   [1 0 1]
%e A331655   [1 0 0]
%e A331655   [0 1 1]
%e A331655   [0 1 0]
%e A331655   [0 0 1]
%Y A331655 Row n=4 of A331039.
%Y A331655 Cf. A188446.
%K A331655 nonn
%O A331655 0,5
%A A331655 _Andrew Howroyd_, Jan 24 2020