A252379 Number of (n+2) X (3+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.

1359, 647, 632, 616, 799, 984, 1114, 1541, 2007, 2417, 3483, 4686, 5828, 8567, 11700, 14758, 21877, 30063, 38137, 56723, 78138, 99344, 147951, 204000, 259586, 386789, 533511, 679105, 1012075, 1396182, 1777420, 2649095, 3654684, 4652846, 6934869

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*(1359 + 647*x + 632*x^2 - 4820*x^3 - 1789*x^4 - 1544*x^5 + 4086*x^6 + 933*x^7 + 599*x^8 - 934*x^9 - 132*x^10 - 38*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:
..2..0..1..2..0....3..1..2..3..1....0..3..0..0..3....0..3..0..0..0
..2..1..0..2..1....1..0..2..1..0....3..3..1..3..3....0..1..2..0..1
..0..0..0..0..0....0..3..0..0..0....1..3..3..1..3....1..0..2..1..0
..2..0..1..2..0....3..1..2..0..1....0..3..0..0..3....0..0..0..0..3
..2..1..0..2..1....1..0..2..1..0....3..3..1..3..3....0..1..2..3..1
..0..0..0..0..3....0..0..0..0..3....1..3..3..1..2....1..0..2..1..0

Crossrefs

Column 3 of A252384.

Sequence in context: A192319 A125270 A316680 * A175696 A023091 A242458

Adjacent sequences: A252376 A252377 A252378 * A252380 A252381 A252382

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved