1,1

Solutions mod p are represented by integers from 0 to p-1. The following equivalences holds for i > 1: There is a prime p such that i is a solution mod p of x^2 = 2 iff i^2-2 has a prime factor > i; i is a solution mod p of x^2 = 2 iff p is a prime factor of i^2-2 and p > i.

Integer i > 1 is a term of this sequence iff i^2-2 has no prime factor > i.

a(1) = 2, since there is no prime p such that 2 is a solution mod p of x^2 = 2. a(2) = 10, since there is no prime p such that 10 is a solution mod p of x^2 = 2 and for each integer i from 3 to 9 there is a prime q such that i is a solution mod q of x^2 = 2 (cf. A059772).

A038873, A059772.

Sequence in context: A099583 A133479 A057753 this_sequence A109723 A053594 A006331

Adjacent sequences: A060512 A060513 A060514 this_sequence A060516 A060517 A060518

nonn

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Mar 24 2001