Number of mobiles (circular rooted trees) with n nodes and 7 leaves.

Terms

a(0) =1a(1) =7a(2) =56a(3) =318a(4) =1408a(5) =5207a(6) =16772a(7) =48410a(8) =127661a(9) =312172a(10) =715827a(11) =1552945a(12) =3210066a(13) =6359208a(14) =12131129a(15) =22374522a(16) =40034564a(17) =69695820a(18) =118346132a(19) =196435550a(20) =319321325a(21) =509215461a(22) =797775355a(23) =1229513719a(24) =1866237409