A204354 Number of (n+2)X3 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly one way, and new values 0..1 introduced in row major order

74, 241, 764, 2399, 7580, 23912, 75324, 237298, 747692, 2355866, 7422792, 23387588, 73689564, 232180522, 731551426, 2304964968, 7262464138, 22882501880, 72097956424, 227165551128, 715751065378, 2255181533318, 7105604131896

Offset

1,1

Comments

Column 1 of A204361

Links

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) +6*a(n-3) +21*a(n-4) -4*a(n-5) -10*a(n-6) +2*a(n-7) -20*a(n-8) +4*a(n-10) for n>13

Example

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

Crossrefs

Sequence in context: A301329 A121809 A204361 * A223907 A232512 A046833

Adjacent sequences: A204351 A204352 A204353 * A204355 A204356 A204357

Keyword

nonn

Author

R. H. Hardin Jan 14 2012

Status

approved