A252258 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 0 2 3 6 or 7.

1331, 1016, 562, 512, 570, 782, 1178, 1670, 2474, 3890, 5642, 8594, 13922, 20498, 31778, 52418, 77858, 121922, 203138, 303170, 477314, 799490, 1196162, 1888514, 3171842, 4751618, 7512578, 12635138, 18940418, 29967362, 50436098, 75629570

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 6*a(n-3) - 6*a(n-4) - 8*a(n-6) + 8*a(n-7) for n>12.

Empirical g.f.: x*(1331 - 315*x - 454*x^2 - 8036*x^3 + 1948*x^4 + 2936*x^5 + 11344*x^6 - 2376*x^7 - 4100*x^8 - 1360*x^9 - 736*x^10 - 176*x^11) / ((1 - x)*(1 - 2*x^3)*(1 - 4*x^3)). - Colin Barker, Dec 03 2018

Example

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

Crossrefs

Column 2 of A252260.

Sequence in context: A323329 A353027 A182371 * A038677 A202457 A252347

Adjacent sequences: A252255 A252256 A252257 * A252259 A252260 A252261

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved