Number of connected transitive 4-valent (or quartic) graphs with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =3a(6) =2a(7) =10a(8) =3a(9) =5a(10) =7a(11) =13a(12) =4a(13) =12a(14) =4a(15) =24a(16) =10a(17) =9a(18) =5a(19) =60a(20) =8a(21) =13a(22) =13a(23) =28a(24) =7a(25) =40a(26) =7