Triangle T(n,f): the number of signed cubic graphs on 2n vertices with f edges of the first sign.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =1a(7) =2a(8) =3a(9) =2a(10) =1a(11) =1a(12) =2a(13) =3a(14) =8a(15) =16a(16) =21a(17) =21a(18) =16a(19) =8a(20) =3a(21) =2a(22) =5a(23) =14a(24) =57a(25) =152a(26) =313a(27) =474a(28) =551a(29) =474