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A331636 Number of nonnegative integer matrices with nonzero rows, total sum n and columns with equal sums. 1
1, 5, 17, 109, 557, 5785, 47357, 596365, 7151841, 106763725, 1622633597, 28757539337, 526858352477, 10758375762109, 230342261913169, 5344946955452877, 130370767029201437, 3394996816992588345, 92801587319328673277, 2681375183085608280093 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..20.

FORMULA

a(n) = Sum_{d|n} A316674(n/d, d).

EXAMPLE

The a(2) = 5 matrices are:

  [1]  [1 0]  [0 1]  [2]  [1 1]

  [1]  [0 1]  [1 0]

CROSSREFS

Cf. A316674.

Sequence in context: A100301 A084167 A267143 * A234797 A062586 A301641

Adjacent sequences:  A331633 A331634 A331635 * A331637 A331638 A331639

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Jan 23 2020

STATUS

approved

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Last modified May 22 00:02 EDT 2022. Contains 353931 sequences. (Running on oeis4.)