The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A296621

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A296621

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

#11 by Susanna Cuyler at Tue Dec 19 18:40:09 EST 2017

STATUS

proposed

approved

#10 by Hugo Pfoertner at Tue Dec 19 10:25:00 EST 2017

STATUS

editing

proposed

#9 by Hugo Pfoertner at Tue Dec 19 10:24:18 EST 2017

LINKS

Wikipedia, <a href="https://en.wikipedia.org/wiki/Distance_(graph_theory)">Distance (graph theory).</a> Wikipedia, <a href="https://en.wikipedia.org/wiki/Floyd%E2%80%93Warshall_algorithm">Floyd-Warshall algorithm.</a>

Wikipedia, <a href="https://en.wikipedia.org/wiki/Floyd%E2%80%93Warshall_algorithm">Floyd-Warshall algorithm.</a>

#8 by Hugo Pfoertner at Tue Dec 19 10:23:28 EST 2017

COMMENTS

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

LINKS

M. Meringer, <a href="https://sourceforge.net/projects/genreg/">GenReg</a>, Generation of regular graphs.

STATUS

proposed

editing

#7 by Hugo Pfoertner at Tue Dec 19 10:18:56 EST 2017

STATUS

editing

proposed

#6 by Hugo Pfoertner at Tue Dec 19 10:16:52 EST 2017

NAME

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

DATA

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

OFFSET

6,3,3

#5 by Hugo Pfoertner at Tue Dec 19 10:00:55 EST 2017

EXAMPLE

.

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.

#4 by Hugo Pfoertner at Tue Dec 19 09:53:39 EST 2017

DATA

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

EXAMPLE

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: 010417622583730089 0 1041762 2583730089 364670 154

CROSSREFS

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

#3 by Hugo Pfoertner at Tue Dec 19 09:43:10 EST 2017

EXAMPLE

n/ 1 2 3 4 5 6 7 6: 0 1

86: 0 3 1

8: 0 3

10: 0 60

12: 0 5457 2391

12: 0 5457 2391 14: 0 258474, 3200871, 37, 1

16: 010417622583730089 364670 154

#2 by Hugo Pfoertner at Tue Dec 19 09:26:20 EST 2017

NAME

allocated for Hugo PfoertnerNumber of 5-regular (quartic) connected graphs on 2*n nodes with diameter k written as irregular triangle T(n,k).

DATA

1, 0, 3, 0, 60, 0, 5457, 2391, 0, 258474, 3200871, 37, 1

OFFSET

6,3

EXAMPLE

Triangle begins:

Diameter

n/ 1 2 3 4 5 6 7 6: 0 1

8: 0 3

10: 0 60

12: 0 5457 2391 14: 0 258474, 3200871, 37, 1

16:

KEYWORD

allocated

nonn,tabf,more

AUTHOR

Hugo Pfoertner, Dec 19 2017

STATUS

approved

editing