A223286 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, diagonal or antidiagonal neighbor moves across an icosahedral edge.
160000, 1875, 81057, 1048923, 28271577, 473368227, 10801441521, 200475062187, 4265203621833, 82829709506163, 1709099202398433, 33866115603026427, 689396112362771001, 13783610690189186115, 278907343566603743697
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..1..4....0..2..0....0..2..8....0..5..9....0..5..0....0..2..3....0..1..6 ..4..1..0....0..5..0....0..2..0....0..5..0....0..1..0....0..2..8....4..1..4 ..6..1..6....9..5..9....3..2..0....0..1..0....6..1..0....8..2..3....4..1..6 ..6..7..6....9..8..9....8..2..3....4..1..0....0..1..4....3..2..3....6..1..4 .11..7.11...13..8..2....8..2..3....0..1..6....4..1..6....3..4..3....6..1..4 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
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 13*a(n-1) +278*a(n-2) -2372*a(n-3) -11584*a(n-4) +98256*a(n-5) +68096*a(n-6) -1208064*a(n-7) +753664*a(n-8) +4509696*a(n-9) -4485120*a(n-10) -4571136*a(n-11) +4718592*a(n-12) for n>13
Comments