cp's OEIS Frontend

A223203 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 vertical neighbor moves across an icosahedral edge.

%I A223203 #7 Jul 23 2025 03:51:26
%S A223203 1,15,657,90111,39868737,57728430255,275769851453745,
%T A223203 4367470887097715487,230051556728875753924449,
%U A223203 40390820217552511124819066703
%N A223203 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 vertical neighbor moves across an icosahedral edge.
%C A223203 Diagonal of A223209
%e A223203 Some solutions for n=3
%e A223203 ..0..2..0....0..5..7....0..5..0....0..5..0....0..5..7....0..2..0....0..1..6
%e A223203 ..1..0..2....5..0..5....2..0..5....5..0..5....5..7.11....2..3..2....1..0..1
%e A223203 ..0..5..0....0..5..9....0..2..0....0..5..7....7.11.12....8..2..3....6..1..6
%e A223203 Face neighbors:
%e A223203 0 -> 1 2 5
%e A223203 1 -> 0 4 6
%e A223203 2 -> 0 3 8
%e A223203 3 -> 2 4 16
%e A223203 4 -> 3 1 17
%e A223203 5 -> 0 7 9
%e A223203 6 -> 1 7 10
%e A223203 7 -> 6 5 11
%e A223203 8 -> 2 9 13
%e A223203 9 -> 8 5 14
%e A223203 10 -> 6 12 17
%e A223203 11 -> 7 12 14
%e A223203 12 -> 11 10 19
%e A223203 13 -> 8 15 16
%e A223203 14 -> 9 11 15
%e A223203 15 -> 14 13 19
%e A223203 16 -> 3 13 18
%e A223203 17 -> 4 10 18
%e A223203 18 -> 16 17 19
%e A223203 19 -> 15 18 12
%K A223203 nonn
%O A223203 1,2
%A A223203 _R. H. Hardin_ Mar 18 2013