A252187 Number of (n+2) X (3+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 1 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 1 3 6 or 7.

2055, 2610, 3705, 5460, 8945, 13737, 20974, 34209, 53194, 82196, 134418, 210132, 325600, 533076, 835480, 1296248, 2123352, 3332064, 5172904, 8475744, 13308784, 20667656, 33867888, 53196432, 82622920, 135401616, 212708560, 330396488

Offset

1,1

Comments

Column 3 of A252192.

Links

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

Formula

Empirical: a(n) = 7*a(n-3) -14*a(n-6) +8*a(n-9) for n>15.

Example

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

Crossrefs

Cf. A252192.

Sequence in context: A084550 A020400 A068723 * A252509 A250331 A234772

Adjacent sequences: A252184 A252185 A252186 * A252188 A252189 A252190

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved