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A252225 Number of (n+2) X (5+2) 0..2 arrays with every 3 X 3 subblock row and column sum 2 3 or 4 and every diagonal and antidiagonal sum not 2 3 or 4. 1
2458, 22256, 73826, 160688, 412514, 1339010, 4297634, 13186856, 40282992, 123998850, 382415504, 1178020562, 3627007218, 11168774306, 34396342056, 105928920848, 326217328994, 1004613387440, 3093802840514, 9527668767266 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 3*a(n-1) - a(n-2) + 3*a(n-3) + 3*a(n-4) - a(n-5) - a(n-6) for n>8.

Empirical g.f.: 2*x*(1229 + 7441*x + 4758*x^2 - 22954*x^3 - 34933*x^4 - 11816*x^5 + 7145*x^6 + 4720*x^7) / ((1 - x + 2*x^2 - x^3)*(1 - 2*x - 3*x^2 - x^3)). - Colin Barker, Dec 02 2018

EXAMPLE

Some solutions for n=4:

..0..2..0..2..0..1..1....1..1..2..1..1..0..2....1..0..2..0..2..0..2

..2..0..2..0..2..0..1....0..2..0..2..0..2..0....1..2..0..2..0..2..0

..0..2..0..2..0..2..1....2..0..2..0..2..0..2....1..0..2..0..2..0..1

..2..0..2..0..2..0..2....0..2..0..2..0..2..0....1..2..0..2..0..2..1

..0..2..0..2..0..2..0....2..0..2..0..2..0..2....1..0..2..0..2..0..2

..1..1..1..0..1..1..1....0..2..0..1..1..1..1....0..2..0..2..0..2..0

CROSSREFS

Column 5 of A252228.

Sequence in context: A252105 A252098 A252097 * A283640 A043588 A043798

Adjacent sequences:  A252222 A252223 A252224 * A252226 A252227 A252228

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 15 2014

STATUS

approved

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Last modified October 26 04:27 EDT 2021. Contains 348256 sequences. (Running on oeis4.)