A252237 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 1 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 1 3 4 6 or 7

858, 3896, 16056, 43848, 215424, 932024, 2568432, 12882368, 56984208, 157483872, 797509248, 3566733728, 9868152000, 50206873856, 225779393856, 624968085888, 3187016753664, 14371363263104, 39789382386432, 203137189250048

Offset

1,1

Comments

Column 2 of A252243

Links

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

Formula

Empirical: a(n) = 118*a(n-3) -4264*a(n-6) +55168*a(n-9) -225280*a(n-12) +262144*a(n-15) for n>16

Example

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

Crossrefs

Sequence in context: A307330 A046394 A163304 * A284074 A345548 A345801

Adjacent sequences: A252234 A252235 A252236 * A252238 A252239 A252240

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved