Number of products of distinct primes <= prime(n) equal to -1 (mod prime(n)).

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =2a(5) =1a(6) =3a(7) =7a(8) =10a(9) =17a(10) =33a(11) =56a(12) =102a(13) =197a(14) =359a(15) =617a(16) =1128a(17) =2182a(18) =3966a(19) =7488a(20) =14538a(21) =26766a(22) =51232a(23) =95325a(24) =174742a(25) =335555a(26) =657893a(27) =1266230a(28) =2485507a(29) =4793512