A252299 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7

1126, 1031, 1168, 1516, 2350, 3476, 4905, 8198, 12725, 18474, 31440, 49424, 72442, 124128, 195932, 288438, 495208, 783064, 1155314, 1984208, 3140404, 4639378, 7965648, 12613908, 18651858, 32006608, 50702292, 75026642, 128658128

Offset

1,1

Comments

Column 2 of A252305

Links

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

Formula

Empirical: a(n) = 11*a(n-3) -42*a(n-6) +64*a(n-9) -32*a(n-12) for n>24

Example

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

Crossrefs

Sequence in context: A358395 A252906 A203830 * A203063 A237294 A307174

Adjacent sequences: A252296 A252297 A252298 * A252300 A252301 A252302

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved