A223183 Rolling icosahedron footprints: number of nX5 0..11 arrays starting with 0 where 0..11 label vertices of an icosahedron and every array movement to a horizontal, vertical or antidiagonal neighbor moves along an icosahedral edge.

625, 1280, 10880, 103520, 1018720, 10117600, 100734400, 1003652480, 10001217120, 99661921440, 993129226400, 9896517562400, 98618666649920, 982733746858880, 9792929198608800, 97586414236542560, 972447371181052000

Offset: 1

Author

R. H. Hardin Mar 18 2013

Keywords

• nonn

Comments

Column 5 of A223186

Examples

			Some solutions for n=3
..0..6..2..0..1....0..1..2..6..0....0..5..6..0..2....0..7.11..3..7
..2..0..6..2..8....2..8..4..2..6....6..0..2..1..8....1..3..9.11..3
..1..2..0..1..3....1..2..6..0..2....2..1..8..3..1....7.11..3..9.11
Vertex neighbors:
0 -> 1 2 5 6 7
1 -> 0 2 3 7 8
2 -> 0 1 4 6 8
3 -> 1 7 8 9 11
4 -> 2 6 8 9 10
5 -> 0 6 7 10 11
6 -> 0 2 4 5 10
7 -> 0 1 3 5 11
8 -> 1 2 3 4 9
9 -> 3 4 8 10 11
10 -> 4 5 6 9 11
11 -> 3 5 7 9 10
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 18*a(n-1) -114*a(n-2) +436*a(n-3) -1171*a(n-4) +2198*a(n-5) -2626*a(n-6) +1520*a(n-7) +79*a(n-8) -490*a(n-9) +156*a(n-10) +20*a(n-11) -16*a(n-12) for n>14