A204363 Number of (n+2)X3 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..2 introduced in row major order

74, 212, 555, 891, 2419, 6121, 13693, 38041, 99753, 256077, 702265, 1904821, 5140593, 14093533, 38567033, 105514613, 289594209, 794670109, 2180840713, 5989829701, 16450772689, 45183870253, 124126578969, 340996458069

Offset

1,1

Comments

Column 1 of A204370

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -7*a(n-2) +3*a(n-3) -6*a(n-4) +12*a(n-5) +14*a(n-6) -84*a(n-7) +164*a(n-8) -292*a(n-9) +392*a(n-10) -392*a(n-11) +640*a(n-12) -896*a(n-13) +64*a(n-14) +2176*a(n-15) -3584*a(n-16) +2304*a(n-17) -512*a(n-18)

Example

Some solutions for n=5
..0..0..1....0..0..0....0..0..0....0..0..1....0..0..1....0..0..1....0..1..2
..1..0..0....0..0..0....1..1..1....0..0..0....1..1..1....2..0..2....2..2..2
..0..0..0....0..1..1....2..2..2....0..0..1....1..1..1....0..0..0....2..2..2
..2..0..0....0..0..0....0..0..0....1..0..0....2..2..2....0..0..0....2..1..1
..2..2..0....0..1..0....1..1..1....0..0..0....2..2..2....1..1..1....2..2..2
..2..2..2....0..1..0....1..1..1....1..0..0....1..2..1....0..0..0....2..0..2
..2..2..0....0..1..0....2..2..2....1..2..0....0..2..2....1..1..1....2..0..2

Crossrefs

Sequence in context: A044406 A044787 A204370 * A051970 A300604 A301329

Adjacent sequences: A204360 A204361 A204362 * A204364 A204365 A204366

Keyword

nonn

Author

R. H. Hardin Jan 14 2012

Status

approved