A296621 - OEIS

A296621

Number of 5-regular (quintic) connected graphs on 2*n nodes with diameter k written as irregular triangle T(n,k).

1, 0, 3, 0, 60, 0, 5457, 2391, 0, 258474, 3200871, 37, 1, 0, 1041762, 2583730089, 364670, 154, 0

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OFFSET

3,3

COMMENTS

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

LINKS

M. Meringer, GenReg, Generation of regular graphs.

EXAMPLE

Triangle begins:

Diameter

n/ 1 2 3 4 5

6: 0 1

8: 0 3

10: 0 60

12: 0 5457 2391

14: 0 258474 3200871 37 1

16: 0 1041762 2583730089 364670 154

The adjacency matrix of the unique 5-regular graph on 14 nodes with diameter 5 is provided as example in A296526.

CROSSREFS

Cf. A006821 (row sums), A068934, A204329, A296525 (number of terms in each row), A296526, A296620.

KEYWORD

nonn,tabf,more

AUTHOR

STATUS

approved