

A129433


Number of isomorphism classes of 6regular multigraphs of order n, loops allowed.


8



1, 4, 13, 66, 384, 3369, 40365, 675368, 14843787, 412444439, 14024069358, 570883006810, 27368160642418, 1525274952640101, 97766102550401217, 7141331463919539567
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

Computed using software at http://users.cecs.anu.edu.au/~bdm/nauty/


LINKS

Table of n, a(n) for n=1..16.
R. C. Read, The enumeration of locally restricted graphs (I), J. London Math. Soc. 34 (1959) 417436. [From Jason Kimberley, Oct 05 2009]


FORMULA

a(n)=N\{S_n[S_6] * S_{3n}[S_2]\} [Equation (5.8) of Read 1959]


CROSSREFS

Cf. A129432, A129422, A129427, A129429, A129431, A129435, A129437
Sequence in context: A005035 A222771 A052415 * A157311 A318600 A096805
Adjacent sequences: A129430 A129431 A129432 * A129434 A129435 A129436


KEYWORD

nonn


AUTHOR

Brendan McKay, Apr 15 2007


EXTENSIONS

Using the formula, new terms a(13), Oct 05 2009, and a(14)..a(16), Nov 09 2009, were computed in MAGMA by Jason Kimberley.


STATUS

approved



