A252309 Number of (4+2)X(n+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

1763, 1516, 2151, 3032, 5230, 8130, 11639, 20350, 31954, 45815, 80430, 126682, 181895, 319918, 504586, 724967, 1276206, 2014186, 2894759, 5098030, 8048554, 11568935, 20378670, 32177962, 46255655, 81487918, 128679466, 184982567

Offset

1,1

Comments

Row 4 of A252305

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
..3..0..0..0..3..0....2..0..1..2..3..1....0..1..2..0..1..2....2..1..0..2..1..0
..0..2..1..0..2..1....1..1..1..1..1..1....3..0..3..0..0..3....0..1..2..0..1..2
..2..3..1..2..0..1....2..1..0..2..1..0....2..1..3..2..1..3....3..0..3..3..0..3
..0..3..0..3..0..0....2..3..1..2..3..1....0..1..2..0..1..2....2..1..0..2..1..0
..0..2..1..3..2..1....1..1..1..1..1..1....0..0..3..0..0..0....0..1..2..0..1..2
..2..0..1..2..0..1....2..1..0..2..1..3....2..1..3..2..1..0....3..0..3..3..0..0

Crossrefs

Sequence in context: A141287 A238050 A213804 * A141039 A205731 A151769

Adjacent sequences: A252306 A252307 A252308 * A252310 A252311 A252312

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved