cp's OEIS Frontend

A208196 Number of n X 3 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or left-upward diagonal neighbors.

%I A208196 #8 Jun 29 2018 06:42:30
%S A208196 5,178,10366,639701,39725054,2468504665,153402542384,9533100532733,
%T A208196 592428713557570,36816123505610549,2287915709208554132,
%U A208196 142181136908012254369,8835760693778126853518,549093000211986917072609
%N A208196 Number of n X 3 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or left-upward diagonal neighbors.
%C A208196 Column 3 of A208201.
%H A208196 R. H. Hardin, <a href="/A208196/b208196.txt">Table of n, a(n) for n = 1..210</a>
%F A208196 Empirical: a(n) = 66*a(n-1) - 222*a(n-2) - 1100*a(n-3) + 363*a(n-4) + 594*a(n-5) - 216*a(n-6) for n>7.
%F A208196 Empirical g.f.: x*(5 - 152*x - 272*x^2 + 561*x^3 + 25*x^4 - 261*x^5 + 72*x^6) / ((1 - 6*x - 3*x^2 + 2*x^3)*(1 - 60*x - 135*x^2 + 108*x^3)). - _Colin Barker_, Jun 29 2018
%e A208196 Some solutions for n=4:
%e A208196 ..0..0..1....0..0..1....0..1..1....0..0..0....0..0..0....0..0..0....0..0..0
%e A208196 ..0..2..0....0..1..0....1..0..2....0..1..0....0..1..2....0..1..0....0..1..2
%e A208196 ..1..2..1....0..0..1....3..0..1....1..2..1....2..1..1....2..1..1....1..1..3
%e A208196 ..3..0..0....1..1..0....1..1..1....0..1..3....0..1..2....0..2..1....1..0..0
%Y A208196 Cf. A208201.
%K A208196 nonn
%O A208196 1,1
%A A208196 _R. H. Hardin_, Feb 24 2012