A210046 Number of (n+1) X 3 0..2 arrays containing all values 0..2 with every 2 X 2 subblock having two distinct values, and new values 0..2 introduced in row major order.

9, 119, 1271, 12377, 114237, 1020363, 8917959, 76781969, 654043429, 5527999491, 46453882975, 388684467193, 3241544130797, 26966567758011, 223909491294007, 1856454655587233, 15374716782125557, 127219112989452339

Offset

1,1

Comments

Column 2 of A210052.

Links

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

Formula

Empirical: a(n) = 14*a(n-1) - 41*a(n-2) - 66*a(n-3) + 100*a(n-4) + 56*a(n-5) - 32*a(n-6).

Empirical g.f.: x*(9 - 7*x - 26*x^2 + 56*x^3 + 24*x^4 - 16*x^5) / ((1 - 6*x - 3*x^2 + 2*x^3)*(1 - 8*x - 4*x^2 + 16*x^3)). - Colin Barker, Jul 14 2018

Example

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

Crossrefs

Cf. A210052.

Sequence in context: A087984 A197544 A234964 * A130652 A054051 A159660

Adjacent sequences: A210043 A210044 A210045 * A210047 A210048 A210049

Keyword

nonn

Author

R. H. Hardin, Mar 16 2012

Status

approved