A210128 Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having one, three or four distinct values, and new values 0..3 introduced in row major order.

81, 2609, 84381, 2731088, 88392872, 2860882075, 92593947153, 2996851648908, 96994674850240, 3139283505544719, 101604556573346177, 3288484744444601296, 106433532896116499960, 3444777094948014560211, 111492016763745516373473

Offset

1,1

Comments

Column 2 of A210134.

Links

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

Formula

Empirical: a(n) = 35*a(n-1) - 81*a(n-2) - 153*a(n-3) + 492*a(n-4) - 292*a(n-5).

Empirical g.f.: x*(81 - 226*x - 373*x^2 + 1475*x^3 - 1022*x^4) / ((1 - x)*(1 - 34*x + 47*x^2 + 200*x^3 - 292*x^4)). - Colin Barker, Jul 14 2018

Example

Some solutions for n=4:
  0 0 0   0 0 0   0 1 1   0 1 0   0 1 1   0 0 1   0 1 1
  0 0 0   1 2 1   2 1 1   1 2 3   0 2 3   0 0 2   2 1 1
  1 2 1   1 3 2   0 2 0   3 1 1   1 1 0   2 3 1   3 0 2
  0 1 3   0 3 0   3 0 1   1 0 2   3 2 3   1 2 0   2 0 1
  1 3 0   0 1 3   2 1 2   3 0 1   3 0 0   1 0 1   1 3 0

Crossrefs

Cf. A210134.

Sequence in context: A295274 A206534 A231859 * A297084 A018223 A206660

Adjacent sequences: A210125 A210126 A210127 * A210129 A210130 A210131

Keyword

nonn

Author

R. H. Hardin, Mar 17 2012

Status

approved