Number of 5-valent trees with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =6a(7) =10a(8) =21a(9) =42a(10) =94a(11) =204a(12) =473a(13) =1098a(14) =2633a(15) =6353a(16) =15641a(17) =38789a(18) =97416a(19) =246410a(20) =628726a(21) =1614292a(22) =4171955a(23) =10839366a(24) =28308678a(25) =74266477a(26) =195667533a(27) =517504253a(28) =1373640355a(29) =3658205088