A252239 Number of (n+2) X (4+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 1 3 4 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 1 3 4 6 or 7.

4708, 43848, 331884, 1179792, 11206944, 84935088, 301990464, 2868905088, 21743273664, 77309413632, 734439412224, 5566277622528, 19791209309184, 188016488368128, 1424967069625344, 5066549580828672, 48132221017595904

Offset

1,1

Comments

Column 4 of A252243.

Links

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

Formula

Empirical: a(n) = 260*a(n-3) - 1024*a(n-6) for n>7.

Empirical g.f.: 4*x*(1177 + 10962*x + 82971*x^2 - 11072*x^3 - 48384*x^4 - 338688*x^5 + 16384*x^6) / ((1 - 4*x^3)*(1 - 256*x^3)). - Colin Barker, Mar 20 2018

Example

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

Crossrefs

Cf. A252243.

Sequence in context: A330836 A107544 A092375 * A234086 A093789 A357607

Adjacent sequences: A252236 A252237 A252238 * A252240 A252241 A252242

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved