A252312 Number of (7+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

5496, 4905, 7492, 10626, 20910, 33862, 48579, 104334, 172130, 244167, 588270, 986138, 1389063, 3730350, 6337034, 8869479, 25958190, 44510186, 62011047, 192163374, 331380650, 460363047, 1475370030, 2552327978, 3540109863

Offset

1,1

Comments

Row 7 of A252305

Links

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

Formula

Empirical: a(n) = 15*a(n-3) -70*a(n-6) +120*a(n-9) -64*a(n-12) for n>19

Example

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

Crossrefs

Sequence in context: A251885 A251878 A251877 * A247924 A031617 A045132

Adjacent sequences: A252309 A252310 A252311 * A252313 A252314 A252315

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved