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A357140
Number of n X n triangular (0,1)-matrices with exactly 2n entries equal to 1 and no zero rows or columns.
1
1, 0, 0, 1, 26, 865, 39268, 2375965, 185974145, 18337523130, 2227232055239, 327003956573263, 57121908284696448, 11712143532463633752, 2786114854266411595229, 761208643373263480081077, 236761580851204534640426709, 83183218467008383189955036015
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OFFSET
0,5
LINKS
Table of n, a(n) for n=0..17.
FORMULA
a(n) = A137252(2n,n).
CROSSREFS
Cf. A137252.
Sequence in context: A160140 A139670 A231282 * A333117 A263945 A335609
Adjacent sequences: A357137 A357138 A357139 * A357141 A357142 A357143
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 14 2022
STATUS
approved

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Last modified October 4 18:26 EDT 2024. Contains 376520 sequences.
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