A223320 Rolling icosahedron footprints: number of nX7 0..11 arrays starting with 0 where 0..11 label vertices of an icosahedron and every array movement to a horizontal or antidiagonal neighbor moves along an icosahedral edge.

15625, 46411625, 142980696625, 443803619416625, 1379464144963464625, 4288761014162797342625, 13334277936752000032650625, 41458126974532997739670258625, 128899204399783389165401518452625

Offset: 1

Author

R. H. Hardin Mar 19 2013

Keywords

• nonn

Comments

Column 7 of A223321

Examples

			Some solutions for n=3
..0..6..0..6..0..1..2....0..6..0..6..0..1..2....0..6..0..6..0..6..2
..0..6..0..6..0..1..3....0..6..0..6..2..6..5....0..6..0..6.10..6.10
..0..6..0..7..3..7..1....0..6..0..6..4..6..4....0..6..0..6..5..6.10
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) = 4313*a(n-1) -4293540*a(n-2) [phone]*a(n-3) -400542201531*a(n-4) [phone]*a(n-5) -2762797384141236*a(n-6) +72983536818080616*a(n-7) -643864107456947520*a(n-8)