A212887 a(n) is the prime p corresponding to the smallest integer k such that k^2 == p (mod prime(n)).

2, 5, 3, 2, 17, 2, 7, 5, 7, 23, 41, 2, 11, 5, 3, 59, 29, 71, 2, 17, 11, 3, 43, 41, 37, 7, 31, 17, 13, 7, 5, 47, 59, 47, 151, 2, 23, 17, 79, 5, 3, 59, 2, 113, 2, 29, 71, 23, 17, 83, 5, 67, 61, 131, 53, 47, 43, 41, 31, 17, 13, 11, 7, 67, 239, 53, 227, 47, 2, 107

Offset: 4

Author

Michel Lagneau, May 29 2012

Keywords

• nonn

Comments

The corresponding values of k are {3, 4, 4, 6, 6, 5, 6, 6, 9, 8, 16, 7, 8, 8, 8, 27, …}

Examples

			a(8) = 17 because 17 == 6^2 mod 19 where 19 = prime(8) and 6 is the smallest k.
Remark : 11 == 7^2 mod 19, but 7 > 6.
		

Links

• Michel Lagneau, Table of n, a(n) for n = 4..10000

Crossrefs

Cf. A000224, A095972.

Programs

Maple

for n from 2 to 100 do:p:=ithprime(n):i:=0:for k from 0 to p-1 while(i=0) do: q:=irem(k^2,p):if type(q,prime)=true then i:=1:printf(`%d, `,q):else fi:od:od: