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A195226 Number of lower triangles of an n X n 0..2 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less 1
3, 15, 155, 3151, 127785, 10322065, 1663418313, 535153390177, 343932423395227, 441776066934784687, 1134608168927438377475, 5828490619001307113164495, 59904949456032239303490933489, 1232191818850202836476827846621041 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A195232

LINKS

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

EXAMPLE

Some solutions for n=4

..2........1........1........1........2........2........0........2

..1.1......1.2......1.1......1.2......1.1......1.1......0.0......1.1

..0.1.1....1.1.2....1.1.1....1.2.2....1.1.0....0.1.1....1.0.1....0.0.0

..0.1.1.0..1.1.1.2..0.1.0.0..1.1.2.2..1.1.0.0..0.0.1.1..1.0.0.0..1.1.0.0

CROSSREFS

Sequence in context: A245069 A317667 A228901 * A264558 A136519 A102556

Adjacent sequences:  A195223 A195224 A195225 * A195227 A195228 A195229

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 13 2011

STATUS

approved

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Last modified May 10 14:04 EDT 2021. Contains 343770 sequences. (Running on oeis4.)