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A144053 Number of n X n binary arrays, symmetric under horizontal reflection, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically. 0
1, 4, 5, 25, 357, 4765, 90553, 3100249, 146194232, 11993787067, 1839157793733, 369768109497405, 136403046959201932, 67251730314890513141, 66275214154448397358578, 79949861700558334494500876 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..16.

CROSSREFS

Sequence in context: A047168 A220538 A187996 * A084465 A056200 A282690

Adjacent sequences:  A144050 A144051 A144052 * A144054 A144055 A144056

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 08 2008

STATUS

approved

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Last modified October 5 07:45 EDT 2022. Contains 357252 sequences. (Running on oeis4.)