A211929 - OEIS

A211929

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, vertical or antidiagonal neighbor, and containing the value n(n+1)/2-7.

0, 0, 0, 6093, 8826873, 3020833719, 276214923832, 11092305676290

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OFFSET

1,4

COMMENTS

Column 6 of A211930

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

Some solutions for n=4

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

..1.2......1.2......1.0......1.2......1.2......1.2......1.2......1.2

..3.1.3....0.3.2....2.3.2....0.3.4....3.1.4....0.3.2....3.1.4....3.4.0

..2.4.2.0..4.1.4.1..4.1.5.2..5.2.0.3..5.2.5.1..1.4.5.0..5.2.3.2..5.1.4.3

CROSSREFS

Sequence in context: A156200 A394315 A236824 * A251994 A201225 A031619

Adjacent sequences: A211926 A211927 A211928 * A211930 A211931 A211932

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 25 2012

STATUS

approved