A252380 Number of (n+2) X (4+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.

1966, 771, 663, 744, 916, 1097, 1361, 1791, 2270, 2976, 4082, 5341, 7204, 10080, 13381, 18273, 25783, 34430, 47252, 66894, 89537, 123120, 174524, 233809, 321745, 456303, 611518, 841752, 1194010, 1600373, 2203148, 3125352, 4189229, 5767329

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*(1966 + 771*x + 663*x^2 - 7120*x^3 - 2168*x^4 - 1555*x^5 + 6249*x^6 + 1211*x^7 + 534*x^8 - 1458*x^9 - 189*x^10 - 14*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:
..2..1..0..2..1..0....2..0..1..2..3..1....2..3..1..2..0..1....2..3..1..2..0..1
..0..1..2..3..1..2....3..0..0..0..3..0....2..1..0..2..1..3....2..1..0..2..1..3
..0..0..0..3..0..0....3..2..1..0..2..1....0..0..0..0..3..0....0..0..0..0..3..0
..2..1..0..2..1..0....2..0..1..2..3..1....2..0..1..2..0..1....2..0..1..2..0..1
..0..1..2..3..1..1....3..0..0..0..3..0....2..1..3..2..1..0....2..1..3..2..1..3
..0..0..0..3..0..3....3..2..1..0..2..1....0..3..0..0..0..0....0..3..0..0..3..0

Crossrefs

Column 4 of A252384.

Sequence in context: A056094 A253528 A235966 * A251023 A193312 A202596

Adjacent sequences: A252377 A252378 A252379 * A252381 A252382 A252383

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved