A234720 - OEIS

A234720

Number of (n+1) X (n+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 7 (constant-stress 1 X 1 tilings).

240, 3976, 33560, 357208, 2557656, 23137720, 157274648, 1310504248, 8760624600

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OFFSET

1,1

LINKS

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

EXAMPLE

Some solutions for n=3:

1 6 3 7 4 0 6 0 2 5 0 3 5 1 7 2 0 5 3 3

3 1 5 2 1 4 3 4 6 2 4 0 1 4 3 5 4 2 7 0

0 5 2 6 5 1 7 1 4 7 2 5 5 1 7 2 1 6 4 4

2 0 4 1 1 4 3 4 7 3 5 1 2 5 4 6 4 2 7 0

CROSSREFS

Diagonal of A234728.

Sequence in context: A005950 A279746 A004536 * A249533 A324070 A145094

Adjacent sequences: A234717 A234718 A234719 * A234721 A234722 A234723

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 30 2013

STATUS

approved