Number of (undirected) paths in C_3 X P_n.

Terms

a(0) =6a(1) =129a(2) =1209a(3) =8856a(4) =57522a(5) =348945a(6) =2031525a(7) =11531712a(8) =64438638a(9) =356590161a(10) =1961459841a(11) =10749416568a(12) =58777575354a(13) =320956083777