A326615 a(n) is the smallest prime p such that Sum_{primes q <= p} Kronecker(n,q) > 0, or 0 if no such prime exists.

2, 11100143, 61981, 3, 2082927221, 5, 2, 11100143, 2, 3, 577, 61463, 2083, 11, 2, 3, 2, 11100121, 5, 2082927199, 1217, 3, 2, 5, 2, 17, 61981, 3, 719, 7, 2, 11100143, 2, 3, 23, 5, 11, 31, 2, 3, 2, 13, 17, 7, 2082927199, 3, 2, 61463, 2, 11100121, 7, 3, 17, 5, 2, 11, 2, 3, 31, 7, 5, 41, 2, 3

Offset: 1

Author

Richard N. Smith, Jul 15 2019

Keywords

• nonn

Links

• Richard N. Smith, Table of n, a(n) for n = 1..4096

Crossrefs

Cf. A306499, A306500.

Programs

PARI

a(n) = my(i=0); forprime(p=2, oo, i+=kronecker(n, p); if(i>0, return(p))) \\ after Jianing Song in A306499

Formula

a(A003658(n)) = A306499(n).

a(n) = 2 iff n == 1 or 7 mod 8 (see A047522).

a(n) = 3 iff n == 4 mod 6 (see A016957).