Number of 3-bead necklaces where each bead is a planted trivalent plane tree [or anything else enumerated by the Catalan numbers], by total number of nodes.
A046342
Number of 3-bead necklaces where each bead is a planted trivalent plane tree [or anything else enumerated by the Catalan numbers], by total number of nodes.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =8a(4) =24a(5) =74a(6) =245a(7) =815a(8) =2796a(9) =9707a(10) =34186a(11) =121562a(12) =436298a(13) =1577310a(14) =5740299a(15) =21008777a(16) =77279892a(17) =285544700a(18) =1059332082a(19) =3944254118a(20) =14734260864a(21) =55207053787a(22) =207421476390a(23) =781283558998
External references
- oeis: A046342