Number of 4-regular 4-edge-connected planar simple graphs on n vertices.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =0a(7) =1a(8) =1a(9) =3a(10) =3a(11) =12a(12) =19a(13) =63a(14) =153a(15) =499a(16) =1473a(17) =4974a(18) =16296a(19) =56102a(20) =192899a(21) =674678a(22) =2381395a(23) =8468424