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A195886 Number of lower triangles of an n X n integer array with all row and column sums zero and all row and column sums of squares <=8 0
1, 1, 5, 65, 1349, 90013, 17612909, 7690681987, 6760358933241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 2 of A195892

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

Some solutions for n=4

..0........0........0........0........0........0........0........0

..2-2......2-2.....-1.1......2-2.....-2.2......2-2......2-2.....-2.2

.-2.2.0...-1.2-1....1-1.0...-2.1.1....0-2.2....0.0.0....0.0.0....0.0.0

..0.0.0.0.-1.0.1.0..0.0.0.0..0.1-1.0..2.0-2.0.-2.2.0.0.-2.2.0.0..2-2.0.0

CROSSREFS

Sequence in context: A234871 A121822 A056245 * A079482 A147625 A157097

Adjacent sequences:  A195883 A195884 A195885 * A195887 A195888 A195889

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 24 2011

STATUS

approved

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Last modified March 18 22:11 EDT 2019. Contains 321305 sequences. (Running on oeis4.)