A252535 Number of (3+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

460, 334, 466, 626, 1120, 1760, 2404, 4304, 6832, 9416, 16864, 26912, 37264, 66752, 106816, 148256, 265600, 425600, 591424, 1059584, 1699072, 2362496, 4232704, 6789632, 9443584, 16919552, 27145216, 37761536, 67655680, 108554240, 151020544

Offset: 1

Author

R. H. Hardin, Dec 18 2014

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 3 of A252532.

Formula

Empirical: a(n) = 6*a(n-3) - 8*a(n-6) for n>8.

Empirical g.f.: 2*x*(230 + 167*x + 233*x^2 - 1067*x^3 - 442*x^4 - 518*x^5 + 1164*x^6 + 128*x^7) / ((1 - 2*x^3)*(1 - 4*x^3)). - Colin Barker, Dec 04 2018