Exponentiation of e.g.f. for primes.

Terms

a(0) =1a(1) =2a(2) =7a(3) =31a(4) =162a(5) =973a(6) =6539a(7) =48410a(8) =390097a(9) =3389877a(10) =31534538a(11) =312151125a(12) =3271508959a(13) =36149187780a(14) =419604275375