A183676 Number of (n+1) X 4 0..7 arrays with every 2 X 2 subblock summing to 14.

13448, 54496, 252920, 1287136, 7003928, 40112416, 239241080, 1474919776, 9347624408, 60651538336, 401609136440, 2707018165216, 18536292500888, 128729069556256, 905422420235000, 6442255273423456, 46323252106113368

Offset

1,1

Comments

Column 3 of A183680.

Links

R. H. Hardin, Table of n, a(n) for n = 1..150

Formula

Empirical: a(n) = 36*a(n-1) - 546*a(n-2) + 4536*a(n-3) - 22449*a(n-4) + 67284*a(n-5) - 118124*a(n-6) + 109584*a(n-7) - 40320*a(n-8).

Empirical g.f.: 8*x*(1681 - 53704*x + 704209*x^2 - 4882912*x^3 + 19182706*x^4 - 42244048*x^5 + 47564208*x^6 - 20643840*x^7) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)*(1 - 6*x)*(1 - 7*x)*(1 - 8*x)). - Colin Barker, Apr 03 2018

Example

Some solutions for 3 X 4:
..3..3..3..0....6..0..1..4....1..2..0..6....5..3..4..3....4..7..3..6
..6..2..6..5....1..7..6..3....4..7..5..3....6..0..7..0....0..3..1..4
..3..3..3..0....6..0..1..4....3..0..2..4....4..4..3..4....6..5..5..4

Crossrefs

Cf. A183680.

Sequence in context: A238176 A035917 A332387 * A204394 A250818 A271210

Adjacent sequences: A183673 A183674 A183675 * A183677 A183678 A183679

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved