A383974 - OEIS

A383974

Number of connected subsets of n edges of the icosahedron up to the 120 rotations and reflections of the icosahedron.

1, 1, 2, 8, 27, 126, 557, 2503, 10270, 37542, 114926, 283958, 552542, 866843, 1129291, 1250835, 1195298, 993613, 720889, 456329, 251444, 119989, 49269, 17238, 5113, 1257, 262, 46, 8, 1, 1

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OFFSET

0,3

COMMENTS

Connected subsets of edges are also called "polysticks," "polyedges," and "polyforms."

These are "free" polyforms, in that two polyforms are equivalent if one can be mapped to the other using the 120 symmetries of the icosahedron.

LINKS

Table of n, a(n) for n=0..30.

Peter Kagey, Illustration of a(3).

CROSSREFS

Cf. A333333 (cube, row 3), A383490 (dodecahedron), A383973 (octahedron, row 3), A383975 (tetrahedron, row 3).

Sequence in context: A150711 A150712 A150713 * A276940 A287204 A391918

Adjacent sequences: A383971 A383972 A383973 * A383975 A383976 A383977

KEYWORD

nonn,fini,full

AUTHOR

Peter Kagey, May 16 2025

EXTENSIONS

a(11)-a(30) from Bert Dobbelaere, May 25 2025

STATUS

approved