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A144240 Number of n X n binary arrays, symmetric about both diagonal and antidiagonal, with every 1 adjacent to at least one other 1 both bishopwise and rookwise but with no three 1s in a row bishopwise or rookwise. 0
1, 2, 1, 5, 4, 10, 32, 89, 174, 2023, 3612, 30003, 170438, 1387640, 7339317, 153956133, 877660696, 18345445123, 211690980458, 5237531076262 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..20.

CROSSREFS

Sequence in context: A019473 A056605 A091802 * A233525 A209143 A243274

Adjacent sequences: A144237 A144238 A144239 * A144241 A144242 A144243

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 15 2008

STATUS

approved

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Last modified November 28 19:17 EST 2022. Contains 358421 sequences. (Running on oeis4.)