Number of n-node rooted identity trees of height at most 4.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =5a(6) =7a(7) =10a(8) =13a(9) =18a(10) =24a(11) =32a(12) =41a(13) =52a(14) =66a(15) =83a(16) =102a(17) =124a(18) =152a(19) =181a(20) =216a(21) =255a(22) =299a(23) =346a(24) =400a(25) =458a(26) =521a(27) =588a(28) =659a(29) =735