A252272 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 2 3 4 6 or 7

185, 300, 588, 948, 2154, 4702, 7922, 18772, 41890, 71050, 169992, 381820, 648406, 1556716, 3506186, 5956360, 14322682, 32301418, 54882446, 132071184, 298048144, 506441784, 1219178902, 2752229560, 4676738148, 11260602630, 25424209614

Offset

1,1

Comments

Column 2 of A252278

Links

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

Formula

Empirical: a(n) = 17*a(n-3) -90*a(n-6) +188*a(n-9) -184*a(n-12) +89*a(n-15) -21*a(n-18) +2*a(n-21) for n>22

Example

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

Crossrefs

Sequence in context: A156059 A244248 A129311 * A247529 A301991 A136048

Adjacent sequences: A252269 A252270 A252271 * A252273 A252274 A252275

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved