Number of primes <= n-th Bell number.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =6a(5) =15a(6) =46a(7) =151a(8) =570a(9) =2376a(10) =10961a(11) =54941a(12) =297220a(13) =1720725a(14) =10602541a(15) =69176095a(16) =475881437a(17) =3439093081a(18) =26026621617a(19) =205694058211