A286756 Irregular triangle T(n,k) for 0 <= k < 5n/2: T(n,k) = number of vertices of the cube-connected cycle graph of order n that are at a distance k from a designated vertex.

1, 1, 1, 2, 2, 2, 1, 1, 3, 4, 6, 6, 3, 1, 1, 3, 5, 8, 11, 13, 13, 8, 2, 0, 1, 3, 6, 10, 16, 24, 31, 32, 23, 11, 3, 0, 1, 3, 6, 11, 18, 29, 43, 58, 72, 71, 47, 19, 5, 1, 0, 1, 3, 6, 12, 20, 34, 55, 83, 120, 154, 162, 131, 77, 29, 7, 2, 0

Offset

1,4

Comments

The cube-connected cycle graph of order n is a vertex transitive graph with n*2^n vertices and degree 3.

The radius of the graph is floor(5n/2)-1 for n<=3 and floor(5n/2)-2 for n>3.

Links

Andrew Howroyd, Table of n, a(n) for n = 1..744

Eric Weisstein's World of Mathematics, Cube-Connected Cycle Graph

Example

Triangle starts:
1, 1
1, 2, 2, 2, 1
1, 3, 4, 6, 6, 3, 1
1, 3, 5, 8,  11, 13, 13, 8, 2, 0
1, 3, 6, 10, 16, 24, 31, 32, 23, 11, 3, 0
1, 3, 6, 11, 18, 29, 43, 58, 72, 71, 47, 19, 5, 1, 0
1, 3, 6, 12, 20, 34, 55, 83, 120, 154, 162, 131, 77, 29, 7, 2, 0
...
The order 3 graph has 24 vertices. For k=1 to 6 there are 3, 4, 6, 6, 3, 1 vertices at a distance k from any vertex in the graph.

Crossrefs

Row sums are A036289.

Cf. A192191.

Sequence in context: A101677 A364366 A152067 * A193884 A128084 A131823

Adjacent sequences: A286753 A286754 A286755 * A286757 A286758 A286759

Keyword

nonn,tabf

Author

Andrew Howroyd, May 13 2017

Status

approved