cp's OEIS Frontend

A269291 Number of 3 X n 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three no more than once.

%I A269291 #8 Jan 21 2019 10:07:11
%S A269291 64,2592,62748,1363572,27788292,544118148,10363900428,193439931300,
%T A269291 3554908340004,64533455294868,1159917367905324,20677732339697748,
%U A269291 366084589527655236,6443257191283855908,112830460117748363340
%N A269291 Number of 3 X n 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three no more than once.
%H A269291 R. H. Hardin, <a href="/A269291/b269291.txt">Table of n, a(n) for n = 1..210</a>
%F A269291 Empirical: a(n) = 36*a(n-1) - 378*a(n-2) + 972*a(n-3) - 729*a(n-4) for n>7.
%F A269291 Empirical g.f.: 4*x*(16 + 72*x - 1593*x^2 + 5553*x^3 - 13581*x^4 + 17091*x^5 - 6804*x^6) / (1 - 18*x + 27*x^2)^2. - _Colin Barker_, Jan 21 2019
%e A269291 Some solutions for n=3:
%e A269291 ..0..0..0. .1..1..0. .3..2..0. .1..1..3. .1..0..0. .1..3..3. .1..3..3
%e A269291 ..2..0..2. .3..0..1. .2..0..2. .1..1..0. .0..2..0. .1..1..1. .3..3..0
%e A269291 ..1..1..0. .1..1..0. .3..2..0. .1..1..0. .3..0..2. .1..3..3. .1..1..1
%Y A269291 Row 3 of A269289.
%K A269291 nonn
%O A269291 1,1
%A A269291 _R. H. Hardin_, Feb 21 2016