cp's OEIS Frontend

A229695 Number of defective 3-colorings of a 2Xn 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.

%I A229695 #8 Jul 23 2025 05:46:19
%S A229695 0,3,43,245,1171,5077,20691,80757,305235,1125333,4067091,14461173,
%T A229695 50723091,175867605,603736659,2054728053,6940088019,23284024533,
%U A229695 77651501715,257577229557,850273182099,2794463987157,9147385165779
%N A229695 Number of defective 3-colorings of a 2Xn 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.
%C A229695 Row 2 of A229694
%H A229695 R. H. Hardin, <a href="/A229695/b229695.txt">Table of n, a(n) for n = 1..210</a>
%F A229695 Empirical: a(n) = 9*a(n-1) -27*a(n-2) +27*a(n-3) for n>6.
%F A229695 Empirical: G.f. 3*x^2+43*x^3  -x^4*(245-1034*x+1153*x^2) / (3*x-1)^3. - _R. J. Mathar_, Sep 29 2013
%e A229695 Some solutions for n=3
%e A229695 ..0..1..1....0..1..1....0..1..2....0..1..0....0..0..1....0..1..0....0..0..1
%e A229695 ..0..0..1....0..0..2....1..1..0....1..0..1....1..2..2....2..0..0....2..2..0
%K A229695 nonn
%O A229695 1,2
%A A229695 _R. H. Hardin_, Sep 27 2013