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

1,1

Comments

Column 6 of A223209

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)

Example

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

Crossrefs

Sequence in context: A224015 A059860 A268975 * A224313 A224377 A233024

Adjacent sequences: A223204 A223205 A223206 * A223208 A223209 A223210

Keyword

nonn

Author

R. H. Hardin Mar 18 2013

Status

approved