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 A331712 Number of nonnegative integer matrices with 3 columns and any number of distinct nonzero rows with column sums n and columns in nonincreasing lexicographic order. 2

%I

%S 1,4,59,1987,73567,2451082,75511809,2339355873,69675164655,

%T 1979830442230,54476566524395,1451352437084341,37417988223257669,

%U 936855055418767566,22833066207602691971,542259452455606556087,12569324678636155802527,284784345516796080566156,6313245421004111720679497

%N Number of nonnegative integer matrices with 3 columns and any number of distinct nonzero rows with column sums n 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.

%e The a(1) = 4 matrices are:

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

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

%e [0 0 1]

%Y Column k=3 of A331572.

%Y Cf. A331711.

%K nonn

%O 0,2

%A _Andrew Howroyd_, Jan 25 2020

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Last modified December 8 03:17 EST 2021. Contains 349590 sequences. (Running on oeis4.)