A252133 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 4 6 or 7.

134, 156, 431, 1183, 3163, 8684, 24031, 66098, 181896, 501355, 1381325, 3804929, 10482568, 28879979, 79562524, 219191134, 603866443, 1663632329, 4583248173, 12626699534, 34786145503, 95834674276, 264021357876, 727370136485

Offset

1,1

Comments

Column 2 of A252139.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + a(n-2) + 4*a(n-3) - a(n-4) - 4*a(n-5) - 3*a(n-6) + a(n-8) + a(n-9) for n>11.

Empirical g.f.: x*(134 - 112*x - 15*x^2 - 371*x^3 - 124*x^4 + 143*x^5 + 225*x^6 + 75*x^7 - 13*x^8 - 64*x^9 - 4*x^10) / ((1 - x)*(1 - x - 2*x^2 - 6*x^3 - 5*x^4 - x^5 + 2*x^6 + 2*x^7 + x^8)). - Colin Barker, Mar 20 2018

Example

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

Crossrefs

Cf. A252139.

Sequence in context: A208626 A061491 A274132 * A255795 A048128 A047824

Adjacent sequences: A252130 A252131 A252132 * A252134 A252135 A252136

Keyword

nonn

Author

R. H. Hardin, Dec 14 2014

Status

approved