A252111 Number of (n+2) X (5+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 3 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 3 6 or 7.

1884, 624, 1258, 1956, 3528, 6070, 11760, 21344, 39200, 80832, 147840, 276160, 593664, 1091072, 2059520, 4537344, 8361984, 15877120, 35450880, 65429504, 124620800, 280215552, 517570560, 987381760, 2228158464, 4117102592

Offset

1,1

Links

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

Formula

Empirical: a(n) = 12*a(n-3) - 32*a(n-6) for n>11.

Empirical g.f.: 2*x*(942 + 312*x + 629*x^2 - 10326*x^3 - 1980*x^4 - 4513*x^5 + 24288*x^6 - 512*x^7 + 3308*x^8 + 1152*x^9 + 2304*x^10) / ((1 - 2*x)*(1 + 2*x + 4*x^2)*(1 - 4*x^3)). - Colin Barker, Dec 01 2018

Example

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

Crossrefs

Column 5 of A252114.

Sequence in context: A246478 A237103 A222799 * A259960 A338705 A236613

Adjacent sequences: A252108 A252109 A252110 * A252112 A252113 A252114

Keyword

nonn

Author

R. H. Hardin, Dec 14 2014

Status

approved