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A223435 Generalized Petersen graph (8,2) coloring a rectangular array: number of nX3 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.

%I A223435 #6 Jul 23 2025 04:09:29
%S A223435 144,1376,14112,147520,1562176,16693920,179532768,1939216640,
%T A223435 21008925952,228065409888,2479179661472,26974655289536,
%U A223435 293678536506304,3198664399776288,34848651790913888,379738193353123456
%N A223435 Generalized Petersen graph (8,2) coloring a rectangular array: number of nX3 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
%C A223435 Column 3 of A223440
%H A223435 R. H. Hardin, <a href="/A223435/b223435.txt">Table of n, a(n) for n = 1..210</a>
%F A223435 Empirical: a(n) = 15*a(n-1) -18*a(n-2) -310*a(n-3) +167*a(n-4) +475*a(n-5) -244*a(n-6) -100*a(n-7) +48*a(n-8)
%e A223435 Some solutions for n=3
%e A223435 .13.11.13....9.11..9...12..4..5....9.15.13....6..5.13....5..6.14....6..5..6
%e A223435 .15..9.11....1..9..1....4..3..4...15..9.11....7..6..5....6.14.12....5..6..7
%e A223435 .13.11.13....0..1..2....5..4.12....9.15.13....0..7..6...14.12.14....6.14..6
%K A223435 nonn
%O A223435 1,1
%A A223435 _R. H. Hardin_ Mar 20 2013