A183997 Number of (n+1) X 4 0..2 arrays with all 2 X 2 subblock sums the same.

361, 579, 977, 1887, 3793, 8415, 19217, 47031, 117601, 308799, 822977, 2268807, 6311953, 17963055, 51378737, 149156151, 434130241, 1275821919, 3754108577, 11115905127, 32933734513, 97974065295, 291541674257, 869866334871

Offset

1,1

Comments

Column 3 of A184003.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) - 60*a(n-3) + 85*a(n-4) + 150*a(n-5) - 360*a(n-6) + 396*a(n-8) - 216*a(n-9).

Empirical g.f.: x*(361 - 1587*x - 2497*x^2 + 17685*x^3 - 3474*x^4 - 59088*x^5 + 42012*x^6 + 60804*x^7 - 56376*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Apr 09 2018

Example

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

Crossrefs

Cf. A184003.

Sequence in context: A325882 A255787 A219340 * A211822 A233552 A176899

Adjacent sequences: A183994 A183995 A183996 * A183998 A183999 A184000

Keyword

nonn

Author

R. H. Hardin, Jan 08 2011

Status

approved