Number of (undirected) Hamiltonian paths in the n-antiprism graph.

Terms

a(0) =120a(1) =408a(2) =1200a(3) =3240a(4) =8330a(5) =20720a(6) =50418a(7) =120760a(8) =285846a(9) =670416a(10) =1560728a(11) =3611020a(12) =8311110a(13) =19042656a(14) =43459344a(15) =98838684a(16) =224091320a(17) =506660240a(18) =1142669766a(19) =2571214756a(20) =5773744326a(21) =12940614624a(22) =28953267050a(23) =64676245192a(24) =144261049680a(25) =321334401528a(26) =714843635370