Reversion of (1 + g.f. for primes).

Terms

a(0) =1a(1) =-2a(2) =5a(3) =-15a(4) =52a(5) =-200a(6) =827a(7) =-3596a(8) =16191a(9) =-74702a(10) =350794a(11) =-1669439a(12) =8029728a(13) =-38963552a(14) =190499461a(15) =-937550897a(16) =4641253152a(17) =-23096403422a(18) =115475977145a(19) =-579799302750