A252525 Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7

750, 595, 460, 535, 546, 649, 823, 1036, 1328, 1756, 2254, 2949, 3882, 5007, 6535, 8608, 11078, 14439, 18930, 24343, 31630, 41368, 53110, 68859, 89778, 115127, 148930, 193720, 248118, 320379, 415794, 532023, 685810, 888376, 1135670, 1461819

Offset

1,1

Comments

Column 1 of A252532

Links

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

Formula

Empirical: a(n) = 4*a(n-3) -3*a(n-6) -4*a(n-9) +4*a(n-12) for n>23

Example

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

Crossrefs

Sequence in context: A071924 A078549 A252524 * A252681 A252532 A252533

Adjacent sequences: A252522 A252523 A252524 * A252526 A252527 A252528

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved