A223207 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 or vertical neighbor moves across an icosahedral edge.
243, 9375, 443451, 22163655, 1127761923, 57728430255, 2960941376139, 151970441720919, 7801619707803603, 400536865551609279, 20564155823714361819, 1055802848340690163431, 54207072655600127312547
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..2..0..1..6.10....0..1..6.10..6.10....0..5..0..2..3..4....0..5..9..5..9..8 ..5..0..1..0..1..6....5..0..1..6..1..6....5..0..2..3.16..3....5..9..5..9..8..9 ..0..2..0..1..6.10....0..1..4..1..6..1....0..2..3..2..3.16....0..5..0..5..9.14 Face neighbors: 0 -> 1 2 5 1 -> 0 4 6 2 -> 0 3 8 3 -> 2 4 16 4 -> 3 1 17 5 -> 0 7 9 6 -> 1 7 10 7 -> 6 5 11 8 -> 2 9 13 9 -> 8 5 14 10 -> 6 12 17 11 -> 7 12 14 12 -> 11 10 19 13 -> 8 15 16 14 -> 9 11 15 15 -> 14 13 19 16 -> 3 13 18 17 -> 4 10 18 18 -> 16 17 19 19 -> 15 18 12
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 77*a(n-1) -1444*a(n-2) +5860*a(n-3) +38744*a(n-4) -300016*a(n-5) +339296*a(n-6) +1286720*a(n-7) -2655360*a(n-8) -56832*a(n-9) +1682944*a(n-10) -149504*a(n-11) -163840*a(n-12)
Comments