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A331643 Number of binary matrices with distinct nonzero rows, a total of n ones and each column with the same number of ones. 1
1, 3, 13, 81, 541, 4803, 47293, 552009, 7088365, 102697083, 1622632573, 28141672449, 526858348381, 10648798871763, 230283520498573, 5317134540336849, 130370767029135901, 3385908728450965323, 92801587319328411133, 2677804893723072559401, 81124826179976677328845 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..21.

FORMULA

a(n) = Sum_{d|n} A331567(n/d, d).

EXAMPLE

The a(2) = 3 matrices are:

  [1 0]  [0 1]  [1 1]

  [0 1]  [1 0]

CROSSREFS

Cf. A331567.

Sequence in context: A201795 A308521 A183278 * A074514 A020014 A184972

Adjacent sequences:  A331640 A331641 A331642 * A331644 A331645 A331646

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Jan 24 2020

STATUS

approved

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Last modified May 13 02:36 EDT 2021. Contains 343836 sequences. (Running on oeis4.)