A252308 Number of (3+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

1303, 1168, 1677, 2287, 3902, 6103, 8650, 14935, 23660, 33855, 58675, 93344, 134047, 232723, 370928, 533559, 927091, 1478960, 2129095, 3700915, 5906480, 8506215, 14788915, 23607344, 34004647, 59126323, 94392368, 135978279, 236446771

Offset

1,1

Comments

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

Crossrefs

Sequence in context: A250728 A071847 A014356 * A277772 A252844 A252845

Adjacent sequences: A252305 A252306 A252307 * A252309 A252310 A252311

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved