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

Terms

a(0) =3a(1) =26a(2) =93a(3) =260a(4) =615a(5) =1278a(6) =2401a(7) =4168a(8) =6795a(9) =10530a(10) =15653a(11) =22476a(12) =31343a(13) =42630a(14) =56745a(15) =74128a(16) =95251a(17) =120618a(18) =150765a(19) =186260a(20) =227703a(21) =275726a(22) =330993a(23) =394200a(24) =466075a(25) =547378a(26) =638901a(27) =741468a(28) =855935a(29) =983190