A252383 Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.

7109, 1928, 1610, 1880, 2310, 2769, 3495, 4601, 5840, 7723, 10599, 13880, 18792, 26302, 34929, 47771, 67413, 90036, 123639, 175043, 234308, 322264, 456822, 612017, 842271, 1194529, 1600872, 2203667, 3125871, 4189728, 5767848, 8182190, 10967441

Offset

1,1

Links

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

Formula

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

Empirical g.f.: x*(7109 + 1928*x + 1610*x^2 - 26556*x^3 - 5402*x^4 - 3671*x^5 + 24411*x^6 + 3073*x^7 + 1204*x^8 - 5846*x^9 - 493*x^10 - 14*x^11) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)). - Colin Barker, Dec 03 2018

Example

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

Crossrefs

Column 7 of A252384.

Sequence in context: A183630 A357478 A189354 * A252350 A251948 A269040

Adjacent sequences: A252380 A252381 A252382 * A252384 A252385 A252386

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved