A223276 Rolling icosahedron face footprints: number of n X n 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

1, 15, 849, 72279, 28271577, 20570223999, 72981761306721, 449769396657137031, 15458246910651549408393, 798321445297149167278062831

Offset

1,2

Comments

Diagonal of A223282

Links

Table of n, a(n) for n=1..10.

Example

Some solutions for n=3
..0..2..3....0..5..0....0..2..8....0..1..4....0..2..3....0..2..0....0..5..9
..0..2..8....9..5..7....0..2..8....4..1..6....3..2..0....3..2..3....0..5..7
..3..2..0....9..5..9....3..2..0....6..1..6....3..2..0....8..2..8....0..5..7
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: A205432 A020240 A281695 * A233019 A270962 A223818

Adjacent sequences: A223273 A223274 A223275 * A223277 A223278 A223279

Keyword

nonn

Author

R. H. Hardin Mar 19 2013

Status

approved