%I #9 May 26 2019 09:58:05
%S 1,1,2,3,2,4,4,6,3,11,4,7,10,10,5,14,5,17,12,11,6,28,10,14,13,21,8,35,
%T 8,22,17,18,17,41,10,19,20,40,11,44,11,31,32,23,12,60,16,36,25,37,14,
%U 49,24,50,27,30,15,93,16,31,40,46,29,64,17,47,32,63,18,96,19,38,49,51,30
%N Number of non-isomorphic I-graphs I(n,j,k) on 2n vertices (1<=j,k<=Floor[(n-1)/2]).
%C The I-graph I(n,j,k) is a graph with vertex set V(I(n,j,k)) = {u_0,u_1,...,u_{n-1},v_0,v_1,...,v_{n-1}} and edge set E(I(n,j,k)) = {u_i u_{i+j}, u_i v_i, v_i v_{i+k} : i=0,...,n-1}, where the subscripts are to be read modulo n. The I-graphs generalize the family of generalized Petersen graphs.
%D I. Z. Bouwer, W. W. Chernoff, B. Monson and Z. Star, The Foster Census (Charles Babbage Research Centre, 1988), ISBN 0-919611-19-2.
%H Marko Boben, Tomaz Pisanski, Arjana Zitnik, <a href="https://doi.org/10.1002/jcd.20054">I-graphs and the corresponding configurations</a> J. Combin. Des. 13 (2005), no. 6, 406--424.
%H B. Horvat, T. Pisanski; A. Zitnik. <a href="https://doi.org/10.1007/s00373-011-1086-2">Isomorphism checking of I-graphs</a>, Graphs Comb. 28, No. 6, 823-830 (2012).
%H M. Watkins, <a href="https://doi.org/10.1016/S0021-9800(69)80116-X">A theorem on Tait colorings with an application to the generalized Petersen graphs</a>, J. Combin. Theory 6 (1969), 152-164.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GraphExpansion.html">Graph Expansion</a>
%Y Cf. A077105, A153847.
%K nonn
%O 3,3
%A _Tomaz Pisanski_, Jan 08 2009