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A144243 Number of n X n binary arrays, symmetric under 90-degree rotation, 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, 3, 2, 10, 36, 77, 170, 1539, 2778, 26239, 152082, 1317122, 7797811, 129473317, 857792500, 17986500145, 205469564882 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..19.

CROSSREFS

Sequence in context: A122147 A141486 A184344 * A125210 A098434 A212634

Adjacent sequences:  A144240 A144241 A144242 * A144244 A144245 A144246

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 15 2008

STATUS

approved

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Last modified December 7 20:33 EST 2019. Contains 329849 sequences. (Running on oeis4.)