Number of 7-ary search trees on n keys.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =7a(8) =28a(9) =84a(10) =210a(11) =462a(12) =924a(13) =1758a(14) =3444a(15) =7602a(16) =19278a(17) =52458a(18) =142044a(19) =368130a(20) =905136a(21) =2130198a(22) =4895919a(23) =11280885a(24) =26685540a(25) =65491062a(26) =165584034a(27) =423910572a(28) =1080774261a(29) =2717940687