A343954 a(n) is the number of triangular faces of Johnson solid J_n.

4, 5, 4, 4, 5, 10, 4, 4, 5, 12, 15, 6, 10, 6, 8, 10, 16, 4, 4, 5, 10, 16, 20, 25, 30, 4, 8, 8, 8, 10, 10, 15, 15, 20, 8, 8, 8, 10, 10, 15, 15, 20, 20, 20, 24, 30, 35, 40, 6, 10, 14, 4, 8, 4, 8, 8, 12, 5, 10, 10, 15, 10, 5, 7, 8, 12, 16, 25, 30, 30, 35, 20, 20, 20, 20, 15, 15, 15, 15, 10, 10, 10, 5, 12, 24, 12, 16, 16, 18, 20, 8, 13

Offset

1,1

Links

Table of n, a(n) for n=1..92.

Eric Weisstein's World of Mathematics, Johnson Solid.

Wikipedia, List of Johnson solids.

Formula

a(n) <= A242731(n).

Mathematica

Array[Count[Map[Length, PolyhedronData["J" <> ToString[#], "FaceIndices"]], 3] &, 92] (* Paolo Xausa, Apr 15 2026 *)

Crossrefs

Cf. A242731, A343955, A343956, A343957, A343958, A343959.

Column k = 3 of A394912.

Sequence in context: A329505 A125583 A196619 * A063694 A242624 A068901

Adjacent sequences: A343951 A343952 A343953 * A343955 A343956 A343957

Keyword

nonn,fini,full

Author

Felix Fröhlich, May 05 2021

Extensions

a(74)-a(92) from Pontus von Brömssen, May 27 2025

Status

approved