A252519 Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 2 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 2 4 6 or 7

660, 1169, 2818, 5628, 17804, 47308, 96659, 310987, 832766, 1703099, 5480317, 14683957, 30032974, 96636432, 258941110, 529615317, 1704112781, 4566261438, 9339439627, 30050929581, 80523123527, 164695116796, 529929039498

Offset

1,1

Comments

Column 4 of A252523

Links

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

Formula

Empirical: a(n) = 21*a(n-3) -62*a(n-6) +47*a(n-9) -5*a(n-12) for n>17

Example

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

Crossrefs

Sequence in context: A067235 A113171 A364004 * A014362 A143042 A206642

Adjacent sequences: A252516 A252517 A252518 * A252520 A252521 A252522

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved