A185763 Number of (n+1) X 4 binary arrays with no 2 X 2 subblock trace equal to any horizontal or vertical neighbor 2 X 2 subblock trace.

104, 368, 1408, 5272, 19992, 75192, 284256, 1071200, 4044648, 15253448, 57567440, 217164120, 819446824, 3091567752, 11664944600, 44010709432, 166054788688, 626518324872, 2363865184800, 8918824197024, 33650767785632, 126964068474600

Offset

1,1

Comments

Column 3 of A185769.

Links

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

Formula

Empirical: a(n) = a(n-1) + 10*a(n-2) + 3*a(n-3) - 5*a(n-4) + a(n-5) for n>6.

Empirical g.f.: 8*x*(13 + 33*x - 16*x^3 + 7*x^4 - x^5) / (1 - x - 10*x^2 - 3*x^3 + 5*x^4 - x^5). - Colin Barker, Apr 16 2018

Example

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

Crossrefs

Cf. A185769.

Sequence in context: A258556 A299218 A300032 * A220063 A135441 A188150

Adjacent sequences: A185760 A185761 A185762 * A185764 A185765 A185766

Keyword

nonn

Author

R. H. Hardin, Feb 03 2011

Status

approved