1,4

We include the end points in the range; this affects the value only for n=1.

Conjecture: the sequence contains no 0's. Verified up to n = 100000.

Table of n, a(n) for n=1..100.

(PARI) vector(100, m, sum(k=m^3-m, m^3+m, isprime(k)))

Cf. A110835, A000578, A007531, A034262.

Sequence in context: A317086 A131376 A025840 * A029284 A123275 A112544

Adjacent sequences: A188539 A188540 A188541 * A188543 A188544 A188545

nonn

Franklin T. Adams-Watters, Apr 07 2011

approved