This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A223596 #6 Jul 23 2025 04:16:44 %S A223596 1296,32768,1124064,43725920,1807461152,77164934624,3355919411936, %T A223596 147579242411936,6534353238114336,290550417324168160, %U A223596 12953574232435565408,578463167657721834784,25858916789120236286624 %N A223596 Petersen graph (8,2) coloring a rectangular array: number of nX5 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, diagonal or antidiagonal neighbor moves along an edge of this graph. %C A223596 Column 5 of A223599 %H A223596 R. H. Hardin, <a href="/A223596/b223596.txt">Table of n, a(n) for n = 1..210</a> %F A223596 Empirical: a(n) = 130*a(n-1) -6594*a(n-2) +165720*a(n-3) -2048065*a(n-4) +6908942*a(n-5) +113207352*a(n-6) -1251611248*a(n-7) +1682835356*a(n-8) +35015368440*a(n-9) -160813753152*a(n-10) -226727555648*a(n-11) +2857884027456*a(n-12) -2954267687808*a(n-13) -19659496636672*a(n-14) +47658204103168*a(n-15) +38882496389120*a(n-16) -227511665233920*a(n-17) +120677010550784*a(n-18) +383689593430016*a(n-19) -527695273951232*a(n-20) -28874362912768*a(n-21) +441922152038400*a(n-22) -227408161538048*a(n-23) -76438468296704*a(n-24) +100031633817600*a(n-25) -21626502512640*a(n-26) -5816459460608*a(n-27) +2924872728576*a(n-28) -309237645312*a(n-29) %e A223596 Some solutions for n=3 %e A223596 ..4.12..4.12..4....2.10.12.10..2....4.12.14.12.14....0..8.14.12..4 %e A223596 .10.12.10.12.14....2.10.12.10.12...10.12.10.12.14...10..8.14.12..4 %e A223596 .14..8.14.12.10....8.10..8.10..8...14..8.14.12.14...14.12.14.12..4 %K A223596 nonn %O A223596 1,1 %A A223596 _R. H. Hardin_ Mar 23 2013