cp's OEIS Frontend

A209102 Number of 3 X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

%I A209102 #9 Jul 08 2018 10:48:11
%S A209102 5,82,1326,20928,329064,5171088,81254376,1276752432,20061624144,
%T A209102 315228486048,4953188212416,77829494407872,1222935603647424,
%U A209102 19215999064449408,301941180717342336,4744404717684160512
%N A209102 Number of 3 X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.
%C A209102 Row 3 of A209100.
%H A209102 R. H. Hardin, <a href="/A209102/b209102.txt">Table of n, a(n) for n = 1..210</a>
%F A209102 Empirical: a(n) = 22*a(n-1) - 110*a(n-2) + 180*a(n-3) - 60*a(n-4) for n>5.
%F A209102 Empirical g.f.: x*(5 - 28*x + 72*x^2 - 124*x^3 + 48*x^4) / (1 - 22*x + 110*x^2 - 180*x^3 + 60*x^4). - _Colin Barker_, Jul 08 2018
%e A209102 Some solutions for n=4:
%e A209102 ..0..0..0..0....0..0..0..0....0..0..1..2....0..1..0..2....0..0..1..2
%e A209102 ..1..2..2..2....1..1..1..2....1..2..0..2....1..2..0..1....1..2..0..2
%e A209102 ..1..0..1..1....0..2..0..1....2..0..1..2....1..0..1..2....0..1..2..1
%Y A209102 Cf. A209100.
%K A209102 nonn
%O A209102 1,1
%A A209102 _R. H. Hardin_, Mar 05 2012