a(n) = binomial(prime(n), phi(prime(n) + 1)).

A375337

a(n) = binomial(prime(n), phi(prime(n) + 1)).

Terms

    a(0) =1a(1) =3a(2) =10a(3) =35a(4) =330a(5) =1716a(6) =12376a(7) =75582a(8) =490314a(9) =4292145a(10) =300540195a(11) =17672631900a(12) =7898654920a(13) =960566918220

External references