A209842 Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.

41, 451, 5083, 59563, 715307, 8743851, 108170155, 1348830635, 16906444715, 212615337387, 2679560724395, 33816082486699, 427128352677803, 5397985037899179, 68242648846098347, 862930148771567019

Offset

1,1

Comments

Column 2 of A209848.

Links

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

Formula

Empirical: a(n) = 22*a(n-1) - 127*a(n-2) + 90*a(n-3) + 288*a(n-4) - 400*a(n-5) + 128*a(n-6).

Empirical g.f.: x*(41 - 451*x + 368*x^2 + 1324*x^3 - 1936*x^4 + 640*x^5) / ((1 - x)*(1 - 8*x)*(1 - 13*x + 2*x^2 + 32*x^3 - 16*x^4)). - Colin Barker, Jul 13 2018

Example

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

Crossrefs

Cf. A209848.

Sequence in context: A112748 A173768 A061643 * A211154 A103735 A177491

Adjacent sequences: A209839 A209840 A209841 * A209843 A209844 A209845

Keyword

nonn

Author

R. H. Hardin, Mar 14 2012

Status

approved