Number of bilaterally asymmetric 8-hoops with n symbols and no a-rooted trees.

Terms

a(0) =1a(1) =71a(2) =918a(3) =6667a(4) =33665a(5) =131616a(6) =425866a(7) =1192178a(8) =2977857a(9) =6785605a(10) =14339006a(11) =28451061a(12) =53519713a(13) =96176822a(14) =166119570a(15) =277155796a(16) =448497281a(17) =706337523a(18) =1085753062a(19) =1632969935a(20) =2408039361a(21) =3487969276a(22) =4970360858a(23) =6977601702a(24) =9661669825a(25) =13209605201a(26) =17849708046