cp's OEIS Frontend

A216085 Number of horizontal and antidiagonal neighbor colorings of the odd squares of a 3Xn array with new integer colors introduced in row major order.

%I A216085 #10 Jul 22 2025 23:29:59
%S A216085 1,3,5,42,136,2440,10900,322776,1805632,77360796,514264344,
%T A216085 29562890886,226109935520,16604827619828,142953007039492,
%U A216085 12954736337254696,123560080110698296,13465808369740333664,140585883811112551960
%N A216085 Number of horizontal and antidiagonal neighbor colorings of the odd squares of a 3Xn array with new integer colors introduced in row major order.
%C A216085 Row 3 of A216084
%H A216085 R. H. Hardin, <a href="/A216085/b216085.txt">Table of n, a(n) for n = 1..41</a>
%e A216085 Some solutions for n=4
%e A216085 ..x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..1
%e A216085 ..2..x..0..x....1..x..0..x....2..x..0..x....2..x..3..x....2..x..3..x
%e A216085 ..x..1..x..2....x..2..x..0....x..2..x..1....x..0..x..3....x..2..x..3
%K A216085 nonn
%O A216085 1,2
%A A216085 _R. H. Hardin_ Sep 01 2012