A183666 Number of (n+1) X 4 0..6 arrays with every 2 X 2 subblock summing to 12.

6951, 24745, 100935, 451801, 2163831, 10914505, 57370215, 311907001, 1744391511, 9994250665, 58473101895, 348467631001, 2110957895991, 12976935385225, 80838681063975, 509665597255801, 3248622235733271, 20914068068750185

Offset

1,1

Comments

Column 3 of A183672.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 28*a(n-1) - 322*a(n-2) + 1960*a(n-3) - 6769*a(n-4) + 13132*a(n-5) - 13068*a(n-6) + 5040*a(n-7).

Empirical g.f.: x*(6951 - 169883*x + 1646297*x^2 - 8030449*x^3 + 20565592*x^4 - 25807068*x^5 + 12101040*x^6) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)*(1 - 6*x)*(1 - 7*x)). - Colin Barker, Apr 02 2018

Example

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

Crossrefs

Cf. A183672.

Sequence in context: A059462 A252432 A072870 * A252368 A237468 A028542

Adjacent sequences: A183663 A183664 A183665 * A183667 A183668 A183669

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved