A263054 Number of (n+1) X (2+1) 0..1 arrays with each row and column not divisible by 3, read as a binary number with top and left being the most significant bits.

2, 33, 142, 895, 4314, 22921, 113486, 577071, 2877562, 14455993, 72225582, 361607935, 1807659674, 9041669481, 45205690126, 226052092111, 1130241870522, 5651375017753, 28256745002222, 141284885366175, 706423516399834

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-1) + 12*a(n-2) - 60*a(n-3) - 39*a(n-4) + 195*a(n-5) + 28*a(n-6) - 140*a(n-7).

Empirical g.f.: x*(2 + 23*x - 47*x^2 - 91*x^3 + 193*x^4 + 28*x^5 - 140*x^6) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)*(1 - 5*x)*(1 - 7*x^2)). - Colin Barker, Jan 01 2019

Example

Some solutions for n=4:
..1..0..1....0..0..1....1..0..0....1..0..0....1..0..1....1..0..1....1..0..0
..1..1..1....1..0..0....0..1..0....0..1..0....1..0..1....0..0..1....1..0..1
..1..1..1....1..1..1....1..1..1....0..1..0....0..0..1....1..1..1....0..1..0
..1..1..1....0..0..1....1..0..0....0..1..0....0..1..0....1..0..0....0..0..1
..1..0..1....1..1..1....0..1..0....1..0..1....1..0..0....0..0..1....1..1..1

Crossrefs

Column 2 of A263060.

Sequence in context: A097978 A334197 A156369 * A128152 A052403 A362538

Adjacent sequences: A263051 A263052 A263053 * A263055 A263056 A263057

Keyword

nonn

Author

R. H. Hardin, Oct 08 2015

Status

approved