A251871 Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum not 2 4 5 or 7 and every diagonal and antidiagonal sum 2 4 5 or 7

3092, 7160, 7080, 9936, 18464, 31296, 40816, 93176, 140408, 223728, 450520, 814232, 1178736, 2773304, 4759928, 7729200, 17426968, 32932952, 51615984, 125418104, 233934776, 383184048, 922678360, 1780892312, 2888662896, 7132898744

Offset

1,1

Comments

Column 3 of A251876

Links

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

Formula

Empirical: a(n) = 15*a(n-3) -50*a(n-6) -160*a(n-9) +1056*a(n-12) -1280*a(n-15) for n>22

Example

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

Crossrefs

Sequence in context: A268862 A277786 A092129 * A206132 A187305 A236121

Adjacent sequences: A251868 A251869 A251870 * A251872 A251873 A251874

Keyword

nonn

Author

R. H. Hardin, Dec 10 2014

Status

approved