Number of terms in n-th derivative of a function composed with itself 6 times.

Terms

a(0) =1a(1) =1a(2) =6a(3) =21a(4) =71a(5) =196a(6) =532a(7) =1301a(8) =3101a(9) =6956a(10) =15217a(11) =31951a(12) =65670a(13) =130914a(14) =256150a(15) =489690a(16) =920905a(17) =1699693a(18) =3092751a(19) =5540571a(20) =9802091a(21) =17114237a(22) =29550346a(23) =50444952a(24) =85264328a(25) =142682505a(26) =236649524a(27) =389033014a(28) =634408230a(29) =1026350152