a(n) = binomial(prime(n), composite(n)).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =11a(5) =13a(6) =680a(7) =3876a(8) =245157a(9) =34597290a(10) =84672315a(11) =12875774670a(12) =244662670200a(13) =800472431850