A236011 Number of (n+1) X (1+1) 0..2 arrays colored with the sum of the maximum and minimum values of each 2 X 2 subblock.

81, 306, 1276, 4672, 18784, 70688, 278352, 1062192, 4143280, 15915216, 61792048, 238127760, 922461744, 3560485008, 13777495472, 53218656784, 205822482224, 795331807888, 3075135853232, 11884984533264, 45947260928560

Offset

1,1

Links

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

Formula

Empirical: a(n) = 9*a(n-2) + 14*a(n-3) + 30*a(n-4) + 16*a(n-5) + 8*a(n-6) for n>7.

Empirical g.f.: x*(81 + 306*x + 547*x^2 + 784*x^3 + 586*x^4 + 300*x^5 + 64*x^6) / (1 - 9*x^2 - 14*x^3 - 30*x^4 - 16*x^5 - 8*x^6). - Colin Barker, Oct 20 2018

Example

Some solutions for n=5:
..2..2....1..0....1..2....2..1....0..2....0..2....1..2....2..1....1..0....0..2
..2..1....1..2....2..2....2..2....2..1....1..1....2..1....1..2....0..0....0..0
..0..0....1..2....0..1....1..0....1..1....2..2....1..0....0..1....2..1....1..0
..0..0....0..0....0..0....1..0....1..1....2..2....1..1....0..0....1..1....2..1
..2..2....1..1....2..1....2..2....1..0....1..2....1..1....2..2....1..1....1..1
..1..1....2..0....2..1....2..2....0..2....0..0....2..1....2..2....1..0....2..0

Crossrefs

Column 1 of A236018.

Sequence in context: A236018 A206685 A206270 * A206678 A237463 A237456

Adjacent sequences: A236008 A236009 A236010 * A236012 A236013 A236014

Keyword

nonn

Author

R. H. Hardin, Jan 18 2014

Status

approved