A204636 Number of (n+2)X4 0..3 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..3 introduced in row major order

405, 1884, 5974, 379, 1860, 2239, 8140, 32206, 107738, 407469, 1548886, 5829163, 22096946, 83787824, 317534026, 1203852903, 4564187472, 17303757255, 65603491248, 248721817370, 942974820890, 3575088864265, 13554191235794

Offset

1,1

Comments

Column 2 of A204642

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +a(n-2) -2*a(n-3) -19*a(n-4) -4*a(n-5) +21*a(n-6) +24*a(n-7) +3*a(n-8) -18*a(n-9) -9*a(n-10) for n>13

Example

Some solutions for n=3
..0..0..0..1....0..1..0..2....0..1..0..2....0..0..0..1....0..0..0..0
..1..0..0..0....0..1..0..2....0..1..0..2....0..0..1..1....0..0..0..0
..1..1..0..0....0..1..0..2....0..1..0..2....0..1..1..1....1..1..1..1
..1..1..1..0....0..1..0..2....0..1..0..2....1..1..1..2....0..0..0..0
..0..1..1..1....0..1..0..2....0..1..0..2....1..1..0..0....1..1..1..1

Crossrefs

Sequence in context: A169904 A267893 A151745 * A224527 A219147 A239541

Adjacent sequences: A204633 A204634 A204635 * A204637 A204638 A204639

Keyword

nonn

Author

R. H. Hardin Jan 17 2012

Status

approved