Number of mobiles (circular rooted trees) with n nodes and 6 leaves.

Terms

a(0) =1a(1) =6a(2) =40a(3) =184a(4) =688a(5) =2178a(6) =6116a(7) =15493a(8) =36203a(9) =78954a(10) =162537a(11) =318261a(12) =596881a(13) =1077561a(14) =1881218a(15) =3187222a(16) =5257026a(17) =8463247a(18) =13329249a(19) =20576809a(20) =31189362a(21) =46486870a(22) =68222601a(23) =98696480a(24) =140898502a(25) =198674609a(26) =276933307a(27) =381882149