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A212023 Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-4 0
0, 0, 34, 1793, 44294, 532619, 4022727, 22156544, 97173498, 358710379, 1156729484, 3344765527, 8839882229 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 3 of A212026

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Some solutions for n=4

..0........0........0........0........0........0........0........0

..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2

..3.4.0....3.4.3....3.4.3....3.4.3....3.4.0....1.3.4....3.0.4....1.3.4

..1.5.6.1..5.4.6.4..5.2.0.6..5.6.3.6..1.5.2.6..5.2.1.6..4.1.5.6..5.0.6.0

CROSSREFS

Sequence in context: A202297 A296673 A086881 * A056566 A242177 A187591

Adjacent sequences:  A212020 A212021 A212022 * A212024 A212025 A212026

KEYWORD

nonn

AUTHOR

R. H. Hardin Apr 26 2012

STATUS

approved

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Last modified June 4 17:50 EDT 2020. Contains 334828 sequences. (Running on oeis4.)