Number of terms in 7th derivative of a function composed with itself n times.

Terms

a(0) =1a(1) =15a(2) =74a(3) =237a(4) =599a(5) =1301a(6) =2541a(7) =4586a(8) =7785a(9) =12583a(10) =19536a(11) =29327a(12) =42783a(13) =60893a(14) =84827a(15) =115956a(16) =155873a(17) =206415a(18) =269686a(19) =348081a(20) =444311a(21) =561429a(22) =702857a(23) =872414a(24) =1074345a(25) =1313351a(26) =1594620a(27) =1923859a(28) =2307327a(29) =2751869