Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #9 Oct 15 2024 18:06:54
%S 1,3,5,21,17,281,65,3209,10853,47617,1025,3610317,4097,22361569,
%T 570275061,2515267681,65537,229801424781,262145,10805763650257,
%U 114290395025669,39654899669089,4194305,150858428803209493,140094551951590929,98672497472409697
%N Number of nonnegative integer matrices with total sum n, nonzero rows and distinct columns each with the same sum with columns in decreasing lexicographic order.
%C The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns.
%H Andrew Howroyd, <a href="/A331395/b331395.txt">Table of n, a(n) for n = 1..200</a>
%F a(n) = Sum_{d|n} A331278(n/d, d).
%F a(p) = 2^(p-1) + 1 for prime p.
%Y Cf. A331278.
%K nonn
%O 1,2
%A _Andrew Howroyd_, Jan 15 2020