A223483 Rolling icosahedron face footprints: number of 5Xn 0..19 arrays starting with 0 where 0..19 label faces of an icosahedron and every array movement to a horizontal or antidiagonal neighbor moves across an icosahedral edge

160000, 19683, 455625, 10546875, 288507825, 7939566675, 223894186425, 6318290752875, 178826926010625, 5061686863486275, 143298073856716425, 4056837300096090075, 114852424247153593425, 3251568434305627847475

Offset

1,1

Comments

Row 5 of A223480

Links

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

Formula

Empirical: a(n) = 33*a(n-1) -86*a(n-2) -1564*a(n-3) +7040*a(n-4) -6480*a(n-5) -5088*a(n-6) +5824*a(n-7) -512*a(n-8) for n>13

Example

Some solutions for n=3
..0..5..0....0..5..0....0..5..0....0..5..0....0..5..7....0..5..0....0..5..7
..7..5..7....0..1..4....9..5..0....0..2..0....0..5..7....0..5..0....7..6..7
..9..5..9....4.17..4....0..2..8....0..2..8....7..5..9....0..5..7....7..5..9
..9..8.13....4.17..4....3..2..8....8..2..3....7..5..0....7..6..1....7..5..7
..2..8..2...18.17..4....8.13..8....0..2..3....0..1..0....1..0..2....7..6..1
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: A034212 A268910 A223286 * A202936 A251971 A013897

Adjacent sequences: A223480 A223481 A223482 * A223484 A223485 A223486

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved