A252381 - OEIS

A252381

Number of (n+2) X (5+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.

3020, 1067, 963, 1091, 1305, 1667, 2031, 2598, 3526, 4492, 5983, 8393, 10935, 14845, 21135, 27803, 38046, 54494, 71964, 98787, 141829, 187579, 257809, 370475, 490263, 674134, 969078, 1282700, 1764087, 2536241, 3357327, 4617621, 6639127, 8788771

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-3) - 4*a(n-6) + a(n-9) for n>12.

Empirical g.f.: x*(3020 + 1067*x + 963*x^2 - 10989*x^3 - 2963*x^4 - 2185*x^5 + 9747*x^6 + 1646*x^7 + 710*x^8 - 2288*x^9 - 256*x^10 - 6*x^11) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

EXAMPLE

Some solutions for n=4:

..1..0..2..1..3..2..1....2..3..0..2..1..0..2....0..2..3..0..0..3..0

..0..0..0..3..0..0..3....0..1..2..0..1..2..3....2..1..3..2..1..3..2

..0..1..2..0..1..2..0....0..0..0..0..0..0..3....0..1..2..0..1..2..0

..1..3..2..1..3..2..1....2..1..0..2..1..0..2....0..0..3..0..0..3..0

..3..0..0..3..0..0..3....0..1..2..0..1..2..3....2..1..3..2..1..3..1

..0..1..2..0..1..2..0....0..0..0..0..0..0..3....0..1..2..0..1..2..3

CROSSREFS

Column 5 of A252384.

Sequence in context: A233963 A086746 A031816 * A186394 A236200 A252620

Adjacent sequences: A252378 A252379 A252380 * A252382 A252383 A252384

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 17 2014

STATUS

approved