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A331637 Number of binary matrices with nonzero rows, a total of n ones and each column with the same number of ones. 1
1, 4, 14, 89, 542, 5156, 47294, 570074, 7103343, 104493608, 1622632574, 28411638982, 526858348382, 10699857854372, 230297862127828, 5330284144906443, 130370767029135902, 3390229775073259800, 92801587319328411134, 2679531116538955252338 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = Sum_{d|n} A262809(n/d, d).
EXAMPLE
The a(2) = 4 matrices are:
[1] [1 0] [0 1] [1 1]
[1] [0 1] [1 0]
CROSSREFS
Cf. A262809.
Sequence in context: A352289 A330465 A202139 * A340024 A190481 A316414
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Jan 23 2020
STATUS
approved

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Last modified July 23 10:53 EDT 2024. Contains 374549 sequences. (Running on oeis4.)