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A331713 Number of nonnegative integer matrices with distinct nonzero rows, total sum n each column with the same sum and columns in nonincreasing lexicographic order. 2

%I

%S 1,3,7,18,21,147,77,1119,2270,12273,1089,464200,4229,4148223,32941976,

%T 159812905,66153,10211281004,263321,205923976532,2439257062679,

%U 3086915165084,4199061,1526043270802300,311419986358517,4817701809545446,621665561741298232,1898993198795136209

%N Number of nonnegative integer matrices with distinct nonzero rows, total sum n each column with the same sum and columns in nonincreasing lexicographic order.

%C The condition that the columns be in nonincreasing order is equivalent to considering nonequivalent matrices up to permutation of columns.

%F a(n) = Sum_{d|n} A331572(n/d, d).

%e The a(2) = 3 matrices are:

%e [1 0] [1 1] [2]

%e [0 1]

%Y Cf. A331572.

%K nonn

%O 1,2

%A _Andrew Howroyd_, Jan 25 2020

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Last modified October 15 18:54 EDT 2021. Contains 348034 sequences. (Running on oeis4.)