A252528 Number of (n+2) X (4+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.

719, 462, 626, 790, 1676, 2504, 3160, 6704, 10016, 12640, 26816, 40064, 50560, 107264, 160256, 202240, 429056, 641024, 808960, 1716224, 2564096, 3235840, 6864896, 10256384, 12943360, 27459584, 41025536, 51773440, 109838336

Offset: 1

Author

R. H. Hardin, Dec 18 2014

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 4 of A252532.

Formula

Empirical: a(n) = 4*a(n-3) for n>5.

Empirical g.f.: x*(719 + 462*x + 626*x^2 - 2086*x^3 - 172*x^4) / (1 - 4*x^3). - Colin Barker, Dec 04 2018