cp's OEIS Frontend

A223476 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 or antidiagonal neighbor moves across an icosahedral edge.

%I A223476 #7 Jul 23 2025 04:12:21
%S A223476 1,27,2025,421875,288507825,622332801675,4468456626780825,
%T A223476 104443823338086658275,8163685522687864520397825,
%U A223476 2101858460730043160691131026875
%N A223476 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 or antidiagonal neighbor moves across an icosahedral edge.
%C A223476 Diagonal of A223480
%e A223476 Some solutions for n=3
%e A223476 ..0..1..0....0..2..8....0..2..8....0..2..8....0..2..8....0..2..8....0..2..8
%e A223476 ..0..5..7....8..9.14....0..2..3....0..2..8....0..2..0....3..2..8....8..2..3
%e A223476 ..7..5..9...14.11..7....3..4.17....8..2..8....3..2..0....3..2..3....3..4..3
%e A223476 Face neighbors:
%e A223476 0 -> 1 2 5
%e A223476 1 -> 0 4 6
%e A223476 2 -> 0 3 8
%e A223476 3 -> 2 4 16
%e A223476 4 -> 3 1 17
%e A223476 5 -> 0 7 9
%e A223476 6 -> 1 7 10
%e A223476 7 -> 6 5 11
%e A223476 8 -> 2 9 13
%e A223476 9 -> 8 5 14
%e A223476 10 -> 6 12 17
%e A223476 11 -> 7 12 14
%e A223476 12 -> 11 10 19
%e A223476 13 -> 8 15 16
%e A223476 14 -> 9 11 15
%e A223476 15 -> 14 13 19
%e A223476 16 -> 3 13 18
%e A223476 17 -> 4 10 18
%e A223476 18 -> 16 17 19
%e A223476 19 -> 15 18 12
%K A223476 nonn
%O A223476 1,2
%A A223476 _R. H. Hardin_ Mar 20 2013