A212035 - OEIS

A212035

Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any element at a city block distance of two, and containing the value n(n+1)/2-6

0, 0, 34, 5395, 2083264, 208868785, 7959909333

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OFFSET

1,3

COMMENTS

Column 5 of A212036

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

Some solutions for n=4

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

..1.1......1.2......1.2......1.2......0.1......1.1......1.2......1.2

..2.2.3....3.2.4....3.3.1....1.3.4....2.1.0....2.3.3....3.2.4....3.3.4

..4.4.1.0..5.6.0.1..0.0.4.3..4.5.6.2..2.3.3.4..0.0.4.5..4.5.5.6..4.0.1.2

CROSSREFS

Sequence in context: A187708 A231084 A291976 * A292750 A199837 A267916

Adjacent sequences: A212032 A212033 A212034 * A212036 A212037 A212038

KEYWORD

nonn

AUTHOR

R. H. Hardin Apr 27 2012

STATUS

approved