A209823 Number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having one or two distinct values, and new values 0..2 introduced in row major order.

41, 425, 4418, 46034, 479693, 4998707, 52089776, 542809448, 5656428659, 58943677889, 614231589110, 6400693994414, 66699408393545, 695051362232495, 7242888771829388, 75475627574620628, 786505293293909615

Offset

1,1

Comments

Column 2 of A209829.

Links

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

Formula

Empirical: a(n) = 12*a(n-1) - 16*a(n-2) - 6*a(n-3) + 13*a(n-4) - 2*a(n-5).

Empirical g.f.: x*(41 - 67*x - 26*x^2 + 64*x^3 - 10*x^4) / ((1 - x)*(1 - 11*x + 5*x^2 + 11*x^3 - 2*x^4)). - Colin Barker, Jul 13 2018

Example

Some solutions for n=4:
..0..0..0....0..0..1....0..0..0....0..0..1....0..1..2....0..1..0....0..1..0
..0..1..0....2..0..0....0..0..0....1..1..0....0..1..2....0..0..1....1..1..0
..0..0..0....0..2..2....0..0..0....1..0..1....0..1..1....1..0..0....0..0..0
..1..0..1....0..0..2....1..0..0....0..1..0....0..1..2....0..1..0....0..0..0
..0..0..0....0..2..2....0..0..2....0..1..1....0..1..1....0..1..0....1..1..0

Crossrefs

Cf. A209829.

Sequence in context: A196807 A267325 A083761 * A196784 A112748 A173768

Adjacent sequences: A209820 A209821 A209822 * A209824 A209825 A209826

Keyword

nonn

Author

R. H. Hardin, Mar 13 2012

Status

approved