cp's OEIS Frontend

A229632 Number of defective 3-colorings of an nX3 0..2 array connected horizontally, diagonally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.

%I A229632 #8 Jul 23 2025 05:45:52
%S A229632 1,40,244,1496,8800,50084,277996,1513104,8106632,42869740,224232436,
%T A229632 1161920760,5972173872,30479422388,154582269500,779632820512,
%U A229632 3912450838808,19545592617532,97246103407556,482032538140680
%N A229632 Number of defective 3-colorings of an nX3 0..2 array connected horizontally, diagonally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.
%C A229632 Column 3 of A229637
%H A229632 R. H. Hardin, <a href="/A229632/b229632.txt">Table of n, a(n) for n = 1..210</a>
%F A229632 Empirical: a(n) = 15*a(n-1) -81*a(n-2) +185*a(n-3) -162*a(n-4) +60*a(n-5) -8*a(n-6) for n>7.
%F A229632 Empirical: g.f. x -4*x^2*(2*x-5)*(12*x^4-45*x^3+47*x^2-17*x+2) / (2*x^2-5*x+1)^3. - _R. J. Mathar_, Sep 29 2013
%e A229632 Some solutions for n=3
%e A229632 ..0..1..1....0..1..0....0..0..1....0..1..2....0..0..1....0..1..0....0..1..1
%e A229632 ..2..1..0....0..2..0....1..2..0....2..1..0....2..1..2....0..1..0....0..2..0
%e A229632 ..0..1..0....2..1..2....0..2..1....0..1..1....0..1..2....1..2..2....0..1..2
%K A229632 nonn
%O A229632 1,2
%A A229632 _R. H. Hardin_, Sep 27 2013