Number of rooted planar trees with n non-root nodes: circularly cycling the subtrees at the root gives equivalent trees.

A003239

Number of rooted planar trees with n non-root nodes: circularly cycling the subtrees at the root gives equivalent trees.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =26a(6) =80a(7) =246a(8) =810a(9) =2704a(10) =9252a(11) =32066a(12) =112720a(13) =400024a(14) =1432860a(15) =5170604a(16) =18784170a(17) =68635478a(18) =252088496a(19) =930138522a(20) =3446167860a(21) =12815663844a(22) =47820447028a(23) =178987624514a(24) =671825133648

External references