A204282 Number of (n+2) X 8 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..2 introduced in row major order.

14141, 735, 778, 982, 996, 1496, 2860, 5500, 13636, 35860, 94404, 256196, 698212, 1901476, 5192548, 14183908, 38740068, 105836132, 289145956, 789940324, 2158150756, 5896171108, 16108597860, 44009496164, 120236167780, 328491237988

Offset

1,1

Comments

Column 6 of A204284.

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>8.

Empirical g.f.: x*(14141 - 41688*x - 1427*x^2 - 1352*x^3 + 82896*x^4 + 2918*x^5 - 53524*x^6 - 128*x^7) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Jun 06 2018

Example

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

Crossrefs

Cf. A204284.

Sequence in context: A206899 A207289 A249192 * A134610 A104825 A184574

Adjacent sequences: A204279 A204280 A204281 * A204283 A204284 A204285

Keyword

nonn

Author

R. H. Hardin, Jan 13 2012

Status

approved