A140419 - OEIS

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A140419

Number of n X n symmetric binary matrices with every element adjacent horizontally (and vertically) to some 0.

0

1, 5, 8, 21, 175, 1984, 27783, 566775, 18973984, 977497059, 72692403175, 7984795118976, 1348773682858701, 345874419612107295, 131649476800621708800, 74856171576736831201899

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OFFSET

2,2

LINKS

Table of n, a(n) for n=2..17.

CROSSREFS

Sequence in context: A036381 A363224 A277369 * A292851 A138023 A120037

Adjacent sequences: A140416 A140417 A140418 * A140420 A140421 A140422

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 17 2008

STATUS

approved