A232150 Number of 2 X n 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally, diagonally or antidiagonally.

1, 23, 191, 1299, 9097, 65837, 474721, 3410799, 24510495, 176212555, 1266835473, 9107139805, 65470085209, 470658881191, 3383528394527, 24323895055139, 174862377541881, 1257070592095501, 9036972483506993, 64966018290364927

Offset

1,2

Links

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

Formula

Empirical: a(n) = 6*a(n-1) + 4*a(n-2) + 25*a(n-3) + 60*a(n-4) - 24*a(n-5) - 72*a(n-6).

Empirical g.f.: x*(1 + 17*x + 49*x^2 + 36*x^3 - 96*x^4 - 72*x^5) / (1 - 6*x - 4*x^2 - 25*x^3 - 60*x^4 + 24*x^5 + 72*x^6). - Colin Barker, Oct 03 2018

Example

Some solutions for n=6.
..1..2..1..1..2..2....0..1..1..2..2..2....1..1..2..0..2..2....1..2..0..2..1..1
..2..0..0..0..1..2....0..1..2..2..2..2....1..2..2..1..1..0....2..1..2..1..2..2

Crossrefs

Row 2 of A232149.

Sequence in context: A167467 A129052 A201859 * A269086 A160083 A140545

Adjacent sequences: A232147 A232148 A232149 * A232151 A232152 A232153

Keyword

nonn

Author

R. H. Hardin, Nov 19 2013

Status

approved