A252537 Number of (5+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

546, 676, 1114, 1676, 4420, 7184, 11456, 31136, 50560, 83840, 232192, 376832, 639488, 1789952, 2904064, 4990976, 14049280, 22790144, 39428096, 111312896, 180551680, 313425920, 886177792, 1437335552, 2499411968, 7072120832

Offset

1,1

Links

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

Formula

Empirical: a(n) = 12*a(n-3) - 32*a(n-6) for n>8.

Empirical g.f.: 2*x*(273 + 338*x + 557*x^2 - 2438*x^3 - 1846*x^4 - 3092*x^5 + 4408*x^6 - 136*x^7) / ((1 - 2*x)*(1 + 2*x + 4*x^2)*(1 - 4*x^3)). - Colin Barker, Dec 04 2018

Example

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

Crossrefs

Row 5 of A252532.

Sequence in context: A374239 A353023 A053327 * A099008 A248442 A043479

Adjacent sequences: A252534 A252535 A252536 * A252538 A252539 A252540

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved