%I A112924
%S A112924 0,0,0,1,3,2,3,2,5,3,6,6,4,4,8,12,9,4,12,10,11,19,10,12,15,12,14,22,15,
%T A112924 12,20,16,18,31,18,18,24,16,20,50,21,20,28,22,23,50,27,24,32,24,26
%N A112924 Number of nonisomorphic connected Y-graphs Y(n:i,j,k) with girth 6 on 
               4n vertices (or nodes) for 1<=i,j,k<=n.
%C A112924 A Y-graph Y(n:i,j,k) has 4n vertices arranged in four segments of n vertices. 
               Let the vertices be v_{x,y} for x=0,1,2,3 and y in the integers modulo 
               n. The edges are v_{1,y}v_{1,y+i}, v_{2,y}v_{2,y+j}, v_{2,y}v_{2,
               y+k} and v_{0,y}v_{x,y}, where y=0,1,...,n-1 and x=1,2,3 and the 
               subscript addition is performed modulo n.
%D A112924 I. Z. Bouwer, W. W. Chernoff, B. Monson and Z. Starr (Eds.), "Foster's 
               Census", Charles Babbage Research Centre, Winnipeg, 1988.
%D A112924 J. D. Horton and I. Z. Bouwer, Symmetric Y-graphs and H-graphs, J. Comb. 
               Theory B 53 (1991) 114-129
%e A112924 Y(6:1,1,1) is the smallest Y-graph with girth 6.
%Y A112924 Cf. A112921, A112922, A112923.
%Y A112924 Sequence in context: A134267 A165258 A092962 this_sequence A153092 A165601 
               A054263
%Y A112924 Adjacent sequences: A112921 A112922 A112923 this_sequence A112925 A112926 
               A112927
%K A112924 nonn
%O A112924 3,5
%A A112924 Marko Boben (Marko.Boben(AT)fmf.uni-lj.si), Tomaz Pisanski (Tomaz.Pisanski(AT)fmf.uni-lj.si) 
               and Arjana Zitnik (Arjana.Zitnik(AT)fmf.uni-lj.si), Oct 06 2005