A252315 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 1 3 6 or 7

2498, 1974, 1918, 2579, 5029, 10448, 25875, 68772, 184492, 504259, 1385765, 3809159, 10487354, 28887477, 79569808, 219199326, 603879357, 1663644827, 4583262341, 12626722128, 34786167551, 95834699674, 264021398318

Offset

1,1

Comments

Column 2 of A252321

Links

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

Formula

Empirical: a(n) = a(n-2) +11*a(n-3) +16*a(n-4) +19*a(n-5) -a(n-6) -32*a(n-7) -59*a(n-8) -63*a(n-9) -39*a(n-10) -6*a(n-11) -19*a(n-12) -28*a(n-13) -47*a(n-14) +49*a(n-15) +204*a(n-16) +341*a(n-17) +397*a(n-18) +251*a(n-19) +56*a(n-20) -117*a(n-21) -227*a(n-22) -234*a(n-23) -344*a(n-24) -476*a(n-25) -580*a(n-26) -641*a(n-27) -417*a(n-28) -154*a(n-29) +205*a(n-30) +506*a(n-31) +641*a(n-32) +707*a(n-33) +600*a(n-34) +439*a(n-35) +345*a(n-36) +200*a(n-37) +123*a(n-38) -56*a(n-39) -305*a(n-40) -487*a(n-41) -573*a(n-42) -428*a(n-43) -207*a(n-44) -34*a(n-45) +42*a(n-46) +16*a(n-47) -6*a(n-48) +44*a(n-49) +108*a(n-50) +162*a(n-51) +132*a(n-52) +66*a(n-53) -3*a(n-54) -37*a(n-55) -36*a(n-56) -18*a(n-57) -6*a(n-58) for n>68

Example

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

Crossrefs

Sequence in context: A231456 A190414 A248548 * A131523 A307764 A062120

Adjacent sequences: A252312 A252313 A252314 * A252316 A252317 A252318

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved