A252546 Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 3 4 6 or 7

850, 3880, 15480, 43848, 213120, 881848, 2568432, 12681664, 53297808, 157483872, 782763648, 3314813344, 9868152000, 49199192320, 209132201280, 624968085888, 3120427983360, 13288964395648, 39789382386432, 198807593780224

Offset

1,1

Comments

Row 2 of A252544

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
..3..1..3..3..1..0....3..1..0..3..1..3....3..1..0..3..1..3....2..2..0..2..2..3
..2..2..0..2..2..3....2..2..3..2..2..0....0..0..1..3..0..1....0..2..2..0..2..2
..3..2..2..3..2..2....0..2..2..3..2..2....2..1..1..2..1..1....3..1..3..3..1..0
..3..1..0..0..1..0....3..1..0..3..1..3....0..1..0..0..1..3....2..2..0..2..2..0

Crossrefs

Sequence in context: A235065 A268112 A194618 * A251257 A372114 A252276

Adjacent sequences: A252543 A252544 A252545 * A252547 A252548 A252549

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved