A211961 - OEIS

A211961

Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-5.

0, 0, 67, 10112, 743866, 20556897, 303369413, 2935224783, 20968226394

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OFFSET

1,3

COMMENTS

Column 4 of A211963.

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

Some solutions for n=4

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

..1.2......1.1......1.2......1.2......1.1......1.2......1.2......1.1

..0.2.3....2.3.4....0.3.4....3.4.3....2.3.4....3.2.3....3.3.3....0.0.2

..0.4.3.5..1.5.5.1..5.2.0.3..3.5.0.2..2.0.2.5..4.2.5.4..0.4.2.5..3.4.5.0

CROSSREFS

Cf. A211963.

Sequence in context: A078989 A156121 A280004 * A144940 A211962 A263463

Adjacent sequences: A211958 A211959 A211960 * A211962 A211963 A211964

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 26 2012

STATUS

approved