A210046 - OEIS

%I #9 Jul 14 2018 05:56:05

%S 9,119,1271,12377,114237,1020363,8917959,76781969,654043429,

%T 5527999491,46453882975,388684467193,3241544130797,26966567758011,

%U 223909491294007,1856454655587233,15374716782125557,127219112989452339

%N 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.

%C Column 2 of A210052.

%H R. H. Hardin, <a href="/A210046/b210046.txt">Table of n, a(n) for n = 1..210</a>

%F 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).

%F 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

%e Some solutions for n=4:

%e ..0..0..1....0..0..1....0..0..0....0..1..2....0..1..2....0..0..0....0..1..2

%e ..1..1..1....2..0..0....0..1..0....0..1..2....0..1..2....0..1..0....0..1..2

%e ..2..1..2....2..0..2....1..0..1....0..1..2....0..1..2....0..0..1....0..1..1

%e ..2..2..1....2..0..2....1..1..1....0..1..2....1..1..2....1..0..0....1..0..0

%e ..1..1..2....2..2..2....2..1..2....0..1..1....0..1..1....1..0..2....0..0..2

%Y Cf. A210052.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 16 2012