A252388 Number of (4+2) X (n+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.

651, 570, 616, 744, 1091, 1475, 1880, 2734, 3712, 4817, 7023, 9576, 12499, 18249, 24931, 32608, 47638, 65132, 85253, 124579, 170380, 223079, 326013, 445923, 583912, 853374, 1167304, 1528585, 2234023, 3055904, 4001771, 5848609, 8000323, 10476656

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>14.

Empirical g.f.: x*(651 + 570*x + 616*x^2 - 1860*x^3 - 1189*x^4 - 989*x^5 + 1508*x^6 + 650*x^7 + 276*x^8 - 378*x^9 - 119*x^10 + 12*x^11 + 7*x^12 + 2*x^13) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

Example

Some solutions for n=4:
..0..0..0..0..0..0....2..1..0..2..1..0....2..3..0..0..0..0....2..0..1..2..0..1
..3..1..2..0..1..2....0..0..3..0..0..0....0..2..1..0..2..1....2..1..3..2..1..0
..1..0..2..1..0..2....2..3..1..2..0..1....2..3..1..2..0..1....0..3..0..0..0..0
..0..0..0..0..0..0....2..1..0..2..1..0....0..3..0..0..0..0....2..0..1..2..0..1
..0..1..2..0..1..2....0..0..0..0..0..0....0..2..1..0..2..3....2..1..0..2..1..0
..1..0..2..1..0..2....2..0..1..2..3..1....2..3..1..2..0..1....0..0..0..0..0..0

Crossrefs

Row 4 of A252384.

Sequence in context: A035851 A229797 A110836 * A043605 A255619 A151736

Adjacent sequences: A252385 A252386 A252387 * A252389 A252390 A252391

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved