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A139015 Number of n X n symmetric binary matrices containing no more than five 1s in any 3 X 3 sub-block. 0
1, 2, 8, 44, 530, 11951, 480173, 36013602, 4995124766, 1274350081146, 600639918104102, 522558166736741057, 838554327431003466468, 2483352676636753274201147 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..13.

CROSSREFS

Sequence in context: A157994 A002500 A002833 * A197996 A258622 A290442

Adjacent sequences:  A139012 A139013 A139014 * A139016 A139017 A139018

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 31 2008

STATUS

approved

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Last modified February 25 22:37 EST 2021. Contains 341618 sequences. (Running on oeis4.)