A306503 a(n) is the index in primes of A306500(n), or 0 if A306500(n) = 0.

23338590792, 2946, 1, 2, 3, 1, 5, 2, 1, 3, 1, 5, 1, 5, 16, 1, 6, 7, 1, 2, 3, 38, 2, 1, 1, 5, 3, 1, 11, 11, 1, 1, 2, 9, 1, 13, 2, 1, 6, 15, 1, 3, 8, 4, 5, 1, 43, 1, 2, 8, 1, 1760, 2, 1, 10, 3, 1, 13, 29, 1, 5, 1, 11, 17, 2, 1, 8, 1, 5, 16, 1, 171, 33, 1, 4, 1, 2, 3

Offset: 1

Author

Jianing Song, Feb 19 2019

Keywords

• nonn

Comments

a(n) is the smallest integer k such that Sum_{i=1..k} Kronecker(-A003657(n),prime(i)) > 0, or 0 if no such k exists.

See A306500 for the actual primes.

Examples

			See A306500 for the example that shows a(18) = 7.
		

Crossrefs

Cf. A003657, A306500, A306502.

Programs

PARI

b(n) = my(i=0); forprime(p=2, oo, i+=kronecker(n, p); if(i>0, return(p)))
print1(23338590792, ", "); for(n=4, 300, if(isfundamental(-n), print1(primepi(b(-n)), ", ")))