cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A299529 Number of Johnson solids with exactly n types of faces.

Original entry on oeis.org

5, 35, 35, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Jonathan Sondow, Feb 11 2018

Keywords

Comments

The possible types of faces of a Johnson solid are triangles, squares, pentagons, hexagons, octagons, and decagons. See A299114 comments.

Examples

			Each of the five Johnson solids J12, J13, J17, J51, J84 has only one type of face, so a(1) = 5.
		

Crossrefs

Formula

Sum(n>0, a(n)) = 92, the number of Johnson solids.
a(n) = 0 for n>4.

A299530 Number of regular-faced convex polyhedra (excluding prisms and antiprisms) with exactly n types of faces.

Original entry on oeis.org

10, 45, 38, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Jonathan Sondow, Feb 11 2018

Keywords

Comments

The regular-faced convex polyhedra other than prisms and antiprisms are the Platonic, Archimedean, and Johnson solids.

Examples

			Each of the five Platonic solids, and each of five Johnson solids, has one type of face, so a(1) = 5 + 5 = 10.
Each of ten Archimedean solids, and each of thirty-five Johnson solids, has two types of faces, so a(2) = 10 + 35 = 45.
Each of three Archimedean solids, and each of thirty-five Johnson solids, has three types of faces, so a(3) = 3 + 35 = 38.
Each of seventeen Johnson solids has four types of faces, so a(4) = 17.
		

Crossrefs

Formula

a(n) = 0 for n >= 5.
Showing 1-2 of 2 results.