Number of (directed) Hamiltonian circuits on the n-antiprism graph.

Terms

a(0) =6a(1) =18a(2) =32a(3) =58a(4) =112a(5) =220a(6) =450a(7) =938a(8) =1982a(9) =4220a(10) =9022a(11) =19332a(12) =41472a(13) =89022a(14) =191150a(15) =410506a(16) =881656a(17) =1893634a(18) =4067256a(19) =8735972a(20) =18763898a(21) =40302866a(22) =86566390a(23) =185935764a(24) =399371142a(25) =857808780a(26) =1842486536a(27) =3957474934a(28) =8500256470a(29) =18257692546