A251891 Number of (n+2) X (5+2) 0..3 arrays with every 3 X 3 subblock row and column sum not 2 3 6 or 7 and every diagonal and antidiagonal sum 2 3 6 or 7.

1534, 594, 1260, 1958, 3530, 6072, 11762, 21346, 39202, 80834, 147842, 276162, 593666, 1091074, 2059522, 4537346, 8361986, 15877122, 35450882, 65429506, 124620802, 280215554, 517570562, 987381762, 2228158466, 4117102594

Offset

1,1

Comments

Column 5 of A251894.

Links

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

Formula

Empirical: a(n) = a(n-1) + 12*a(n-3) - 12*a(n-4) - 32*a(n-6) + 32*a(n-7) for n>12.

Empirical g.f.: 2*x*(767 - 470*x + 333*x^2 - 8855*x^3 + 6426*x^4 - 2725*x^5 + 23201*x^6 - 19680*x^7 + 4332*x^8 - 2156*x^9 + 1152*x^10 - 2304*x^11) / ((1 - x)*(1 - 2*x)*(1 + 2*x + 4*x^2)*(1 - 4*x^3)). - Colin Barker, Mar 20 2018

Example

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

Crossrefs

Cf. A251894.

Sequence in context: A278192 A248689 A145982 * A088362 A045123 A252419

Adjacent sequences: A251888 A251889 A251890 * A251892 A251893 A251894

Keyword

nonn

Author

R. H. Hardin, Dec 10 2014

Status

approved