A319081 Number of primes of the form k^3 + n^2 for 0 <= k <= n.

0, 1, 1, 1, 2, 1, 1, 1, 0, 2, 4, 1, 2, 1, 3, 2, 4, 3, 3, 4, 3, 2, 2, 3, 5, 3, 4, 0, 3, 3, 2, 3, 7, 7, 1, 4, 4, 3, 2, 4, 9, 3, 5, 5, 3, 4, 7, 5, 5, 6, 4, 6, 4, 4, 11, 5, 5, 4, 6, 8, 6, 8, 4, 7, 0, 8, 8, 10, 7, 4, 3, 3, 12, 6, 13, 9, 3, 5, 5, 9, 11, 12, 7, 3, 8, 3, 8, 12, 11, 8, 4

Offset

0,5

Links

Table of n, a(n) for n=0..90.

Formula

a(n) = 0 if n is a cube other than 1.

Prog

(PARI) for(n=0, 90, a=sum(k=0, n, isprime(k^3+n^2)); print1(a", "))

Crossrefs

Cf. A066649.

Sequence in context: A089339 A249303 A361167 * A336931 A363953 A182662

Adjacent sequences: A319078 A319079 A319080 * A319082 A319083 A319084

Keyword

nonn

Author

Gionata Neri, Sep 09 2018

Status

approved