A252673 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0, 2, 5, 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0, 2, 5, 6 or 7.

775, 630, 991, 1677, 3573, 7164, 13494, 30552, 63153, 121564, 279871, 585918, 1135346, 2626993, 5528908, 10742509, 24904376, 52533179, 102187158, 237103008, 500642761, 974327011, 2261578642, 4777472917, 9299731171, 21589972325

Offset

1,1

Comments

Column 2 of A252679.

Links

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

Formula

Empirical: a(n) = 22*a(n-3) -178*a(n-6) +713*a(n-9) -1673*a(n-12) +2744*a(n-15) -3188*a(n-18) +2096*a(n-21) -668*a(n-24) +103*a(n-27) +38*a(n-30) -8*a(n-33) for n > 37.

Example

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

Crossrefs

Cf. A252679.

Sequence in context: A365597 A233991 A250087 * A077077 A177845 A177843

Adjacent sequences: A252670 A252671 A252672 * A252674 A252675 A252676

Keyword

nonn

Author

R. H. Hardin, Dec 20 2014

Status

approved