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A331649 Number of binary matrices with n distinct columns and any number of distinct nonzero rows with 2 ones in every column and columns in decreasing lexicographic order. 2
1, 0, 3, 17, 230, 3264, 60338, 1287062, 31900620, 893284155, 27972470286, 967596779631, 36654913572018, 1509052435744560, 67089897326522970, 3203343744126663616, 163486870943294124046, 8881542959996746368420, 511713241494851800728865, 31165957861936237845310435 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns.

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..200

EXAMPLE

The a(2) = 3 matrices are:

   [1 1]  [1 0]  [1 0]

   [1 0]  [1 1]  [0 1]

   [0 1]  [0 1]  [1 1]

CROSSREFS

Row n=2 of A331569.

Sequence in context: A194925 A072350 A181032 * A322737 A201107 A210902

Adjacent sequences:  A331646 A331647 A331648 * A331650 A331651 A331652

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Jan 24 2020

STATUS

approved

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Last modified May 21 11:28 EDT 2022. Contains 353908 sequences. (Running on oeis4.)