A183649 Number of (n+1) X 7 0..4 arrays with every 2 X 2 subblock summing to 8.

115525, 205001, 431125, 1037585, 2764525, 7969001, 24478885, 79273025, 268445725, 944464601, 3434578645, 12856134065, 49365995725, 193928921801, 777715558405, 3178692764705, 13225029670525

Offset

1,1

Comments

Column 6 of A183652.

Links

Table of n, a(n) for n=1..17.

Formula

Empirical: a(n) = 15*a(n-1)-85*a(n-2)+225*a(n-3)-274*a(n-4)+120*a(n-5).

Example

Some solutions for 3 X 7
..0..3..1..3..2..1..1....0..4..1..4..3..0..4....0..1..3..0..3..3..1
..3..2..2..2..1..4..2....4..0..3..0..1..4..0....4..3..1..4..1..1..3
..1..2..2..2..3..0..2....0..4..1..4..3..0..4....0..1..3..0..3..3..1

Crossrefs

Cf. A183652.

Sequence in context: A186791 A069245 A215995 * A237166 A237382 A255080

Adjacent sequences: A183646 A183647 A183648 * A183650 A183651 A183652

Keyword

nonn

Author

R. H. Hardin Jan 06 2011

Status

approved