A209824 Number of (n+1)X4 0..2 arrays with every 2X2 subblock having one or two distinct values, and new values 0..2 introduced in row major order.

218, 4418, 90000, 1842509, 37744836, 773359089, 15846003427, 324684577671, 6652797311199, 136316077450664, 2793121983572647, 57231184269590694, 1172669322792974754, 24028042740488215416, 492335585844232823766

Offset

1,1

Comments

Column 3 of A209829

Links

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

Formula

Empirical: a(n) = 24*a(n-1) -62*a(n-2) -226*a(n-3) +445*a(n-4) +475*a(n-5) -811*a(n-6) +29*a(n-7) +147*a(n-8) -20*a(n-9)

Example

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

Crossrefs

Sequence in context: A253732 A232513 A224741 * A230333 A060530 A252997

Adjacent sequences: A209821 A209822 A209823 * A209825 A209826 A209827

Keyword

nonn

Author

R. H. Hardin, Mar 13 2012

Status

approved