a(n) = 2^p + 3^p + 5^p + 7^p where p = prime(n).

A098139

a(n) = 2^p + 3^p + 5^p + 7^p where p = prime(n).

Terms

    a(0) =87a(1) =503a(2) =20207a(3) =903983a(4) =2026334063a(5) =98111316047

External references