cp's OEIS Frontend

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.

A331395 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.

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%I A331395 #9 Oct 15 2024 18:06:54
%S A331395 1,3,5,21,17,281,65,3209,10853,47617,1025,3610317,4097,22361569,
%T A331395 570275061,2515267681,65537,229801424781,262145,10805763650257,
%U A331395 114290395025669,39654899669089,4194305,150858428803209493,140094551951590929,98672497472409697
%N A331395 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 A331395 The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns.
%H A331395 Andrew Howroyd, <a href="/A331395/b331395.txt">Table of n, a(n) for n = 1..200</a>
%F A331395 a(n) = Sum_{d|n} A331278(n/d, d).
%F A331395 a(p) = 2^(p-1) + 1 for prime p.
%Y A331395 Cf. A331278.
%K A331395 nonn
%O A331395 1,2
%A A331395 _Andrew Howroyd_, Jan 15 2020