A204365 Number of (n+2) X 5 0..2 arrays with every 3 X 3 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.

555, 673, 342, 622, 1042, 2574, 6786, 17586, 47674, 130066, 353650, 965730, 2638290, 7204818, 19683250, 53775634, 146911762, 401369298, 1096561554, 2995850130, 8184812818, 22361325202, 61092253330, 166907136402, 455998778514

Offset

1,1

Comments

Column 3 of A204370.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -6*a(n-4) +4*a(n-6) for n>9.

Empirical g.f.: x*(555 - 992*x - 1677*x^2 - 404*x^3 + 2506*x^4 + 3486*x^5 - 1104*x^6 - 1732*x^7 - 200*x^8) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Jun 07 2018

Example

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

Crossrefs

Cf. A204370.

Sequence in context: A186529 A274901 A075808 * A283158 A043511 A261432

Adjacent sequences: A204362 A204363 A204364 * A204366 A204367 A204368

Keyword

nonn

Author

R. H. Hardin, Jan 14 2012

Status

approved