A359000 Number of undirected n-cycles of the octahedral graph.
8, 15, 24, 16
Offset: 3
Links
- Eric Weisstein's World of Mathematics, Cycle Polynomial
- Eric Weisstein's World of Mathematics, Octahedral Graph
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.
a(1) = 2 since a tetrahedron has 2 distinct nets.
By definition, the zeroth iterated clique graph of a graph G is equal to G itself; since the icosahedron has 12 vertices, a(0)=12. The first iterated clique graph of the icosahedron has 20 vertices; hence, a(1)=20.
K:=CliqueGraph;; g:=Icosahedron;; kg:=K(g);; Order(kg); # It outputs the number of vertices in the first iterated # clique graph of the icosahedron.
By definition, the zeroth iterated clique graph of a graph G is equal to G itself; since the octahedron has 6 vertices, a(0)=6. The first iterated clique graph of the octahedron has 8 vertices; hence, a(1)=8.
Nest[Sqrt[2]^#&, 6, n] (* Omar Antolín-Camarena, May 16 2022 *)
K:=CliqueGraph;; g:=Octahedron;; kg:=K(g);; Order(kg); # It outputs the number of vertices in the first iterated # clique graph of the octahedron.
6 is a term since a cube has 6 faces.
ismult(n, v, vp) = {for (k=1, #v, q = n/v[k]; if ((type(q)== "t_INT") && vecsearch(vp, q), return (1)););} lista(nn) = {v = [4,6,8,12,20]; vp = []; for (n=2, nn, if (vecsearch(v, n) || ismult(n, v, vp), print1(n, ", "); vp = concat(vp, n);););} \\ Michel Marcus, Feb 03 2015
a(0) = 1 because the 0-D regular polytope is the point. a(1) = 2 because the only regular 1-D polytope is the line segment, with 2 vertices, one at each end. a(2) = 0, indicating infinity, because the regular k-gon has k vertices. a(3) = 50 (4 for the tetrahedron, 6 for the octahedron, 8 for the cube, 12 for the icosahedron, 20 for the dodecahedron) = the sum of A053016. a(4) = 773 = 5 + 8 + 16 + 24 + 120 + 600 = sum of A063924. For n>4 there are only the three regular n-dimensional polytopes, the simplex with n+1 vertices, the hypercube with 2^n vertices and the hyperoctahedron = cross polytope = orthoplex with 2*n vertices, for a total of A086653(n) + 1 = 2^n + 3*n + 1 (again restricted to n > 4).
LinearRecurrence[{4, -5, 2}, {1, 2, 0, 50, 773, 48, 83, 150}, 32] (* Georg Fischer, May 03 2019 *)
v[n_] := 2*(If[n == 0, 0, 2^(n - 1)] + 2); Table[v[n], {n, 0, 30}]
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