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 A223280 #6 Jul 23 2025 03:57:12 %S A223280 243,6831,261819,10979127,473368227,20570223999,895927195659, %T A223280 39047604482055,1702160040384051,74204651599582287, %U A223280 3234961829070975771,141029297731894387287,6148230806876335875267,268034791871130540563487 %N A223280 Rolling icosahedron face footprints: number of nX6 0..19 arrays starting with 0 where 0..19 label faces of an icosahedron and every array movement to a horizontal, diagonal or antidiagonal neighbor moves across an icosahedral edge. %C A223280 Column 6 of A223282 %H A223280 R. H. Hardin, <a href="/A223280/b223280.txt">Table of n, a(n) for n = 1..210</a> %F A223280 Empirical: a(n) = 63*a(n-1) -882*a(n-2) +792*a(n-3) +35736*a(n-4) -70768*a(n-5) -246208*a(n-6) +327936*a(n-7) +146432*a(n-8) -180224*a(n-9) %e A223280 Some solutions for n=3 %e A223280 ..0..2..3..2..3..2....0..5..0..1..0..1....0..5..0..5..0..5....0..2..0..1..4..1 %e A223280 ..0..2..8..2..8..2....0..5..0..2..0..2....0..5..0..2..0..1....0..2..0..1..0..1 %e A223280 ..8..2..0..2..8.13....0..5..0..2..3..2....7..5..0..2..0..5....0..1..0..1..6..1 %e A223280 Face neighbors: %e A223280 0 -> 1 2 5 %e A223280 1 -> 0 4 6 %e A223280 2 -> 0 3 8 %e A223280 3 -> 2 4 16 %e A223280 4 -> 3 1 17 %e A223280 5 -> 0 7 9 %e A223280 6 -> 1 7 10 %e A223280 7 -> 6 5 11 %e A223280 8 -> 2 9 13 %e A223280 9 -> 8 5 14 %e A223280 10 -> 6 12 17 %e A223280 11 -> 7 12 14 %e A223280 12 -> 11 10 19 %e A223280 13 -> 8 15 16 %e A223280 14 -> 9 11 15 %e A223280 15 -> 14 13 19 %e A223280 16 -> 3 13 18 %e A223280 17 -> 4 10 18 %e A223280 18 -> 16 17 19 %e A223280 19 -> 15 18 12 %K A223280 nonn %O A223280 1,1 %A A223280 _R. H. Hardin_ Mar 19 2013