A070995 - OEIS

%I #16 Jul 28 2024 19:44:19

%S 1,5,50,17794,174685429024800,1476099903835055889100,

%T 569361345959217303084880851701375547158,

%U 24894339520238610434672964029323166045198384692144,221903632506534809770887023612289701531002339299063461384464526904412590996

%N Number of nonisomorphic (undirected) Cayley graphs for the group Zp x Zp, where Zp is the elementary Abelian group of order p and p is prime. The sequence is index by primes, though starts with 1.

%C The formula comes from a cycle index; There is a similar formula for directed Cayley graphs

%D C. Godsil, On Cayley graph isomorphisms, Ars, Combin., 15:231-246, 1983

%H B. Alspach and M. Mishna, <a href="http://dx.doi.org/10.1016/S0012-365X(02)00319-9">Enumeration of Cayley graphs and digraphs</a>, Discr. Math., 256 (2002), 527-539. [Note: In the third sum of Theorem 4.2 the exponent should be (p^2-1)/2/h(d). - _Sean A. Irvine_ and _Marni Mishna_, Jul 28 2024]

%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a070/A070995.java">Java program</a> (github)

%H M. Mishna, <a href="http://people.math.sfu.ca/~mmishna/PUB/sfu-thesis.pdf">Cayley Graphs </a>

%Y Cf. A049287.

%K nonn

%O 1,2

%A _Marni Mishna_, May 18 2002

%E a(9) from _Sean A. Irvine_, Jul 22 2024