A296525 Maximal diameter of connected k-regular graphs on 2*n nodes written as array T(n,k), 2 <= k < 2*n.

2, 1, 3, 2, 2, 1, 4, 3, 2, 2, 2, 5, 5, 3, 2, 2, 2, 2, 1, 6, 6, 4, 3, 2, 2, 2, 2, 2, 1, 7, 8, 5, 5, 3, 2, 2, 2, 2, 2, 2, 1, 8, 9, 7, 5

Offset

2,1

Comments

The results were found by applying the Floyd-Warshall algorithm to the output of Markus Meringer's GenReg program.

Links

Table of n, a(n) for n=2..46.

L. Caccetta, W. F. Smyth Graphs of maximum diameter, Discrete Mathematics, Volume 102, Issue 2, 20 May 1992, Pages 121-141.

M. Meringer, Regular Graphs.

M. Meringer, GenReg, Generation of regular graphs.

StackOverflow, Algorithm for diameter of graph?.

Wikipedia, Distance (graph theory).

Wikipedia, Floyd-Warshall algorithm.

Example

Table starts:
Degree = 2  3  4  5  6  7  8  9
n= 4 :   2  1
n= 6 :   3  2  2  1
n= 8 :   4  3  2  2  2  1
n=10 :   5  5  3  2  2  2  2  1
...
See example in A296526 for a complete illustration of the irregular table.

Crossrefs

Cf. A068934, A294732 (2nd column of table), A294733, A296524, A296526, A296621.

Sequence in context: A272911 A371014 A284267 * A333766 A333226 A175548

Adjacent sequences: A296522 A296523 A296524 * A296526 A296527 A296528

Keyword

nonn,tabf,more,hard

Author

Hugo Pfoertner, Dec 14 2017

Extensions

a(46) corresponding to the quintic graph on 16 nodes from Hugo Pfoertner, Dec 19 2017

Status

approved