A252530 Number of (n+2) X (6+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.

932, 1000, 1760, 2440, 7184, 13184, 18656, 54464, 101888, 145792, 423680, 800768, 1152512, 3341312, 6348800, 9164800, 26537984, 50561024, 73097216, 211533824, 403570688, 583892992, 1689190400, 3224895488, 4667604992, 13501202432

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.: 4*x*(233 + 250*x + 440*x^2 - 2186*x^3 - 1204*x^4 - 1984*x^5 + 4800*x^6 + 64*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:
..0..1..1..0..1..1..0..1....2..2..3..2..2..3..2..2....2..0..0..3..0..0..3..3
..1..0..1..1..0..1..1..0....3..2..2..3..2..2..3..2....1..0..1..1..0..1..1..0
..0..0..2..0..0..3..0..0....3..0..3..3..1..3..3..0....1..1..0..1..1..0..1..1
..0..1..1..0..1..1..0..1....2..2..3..2..2..3..2..2....3..0..0..3..0..0..3..0
..1..0..1..1..0..1..1..0....3..2..2..3..2..2..3..2....1..0..1..1..0..1..1..0
..0..0..3..0..0..2..0..0....3..0..3..3..0..3..3..0....1..1..0..1..1..0..1..1

Crossrefs

Column 6 of A252532.

Sequence in context: A209810 A035856 A093231 * A105213 A347852 A171348

Adjacent sequences: A252527 A252528 A252529 * A252531 A252532 A252533

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved