A252188 Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 1 3 6 or 7

3341, 3996, 5460, 9233, 14130, 21417, 34532, 55336, 84332, 135776, 218896, 334872, 539664, 871440, 1334792, 2152016, 3477712, 5329992, 8595024, 13894992, 21301832, 34354256, 55548496, 85171272, 137365584, 222131280, 340613192, 549359696

Offset

1,1

Comments

Column 4 of A252192

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>17

Example

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

Crossrefs

Sequence in context: A261656 A231955 A255657 * A270338 A054356 A358312

Adjacent sequences: A252185 A252186 A252187 * A252189 A252190 A252191

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved