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A213049
Primes p such that the order of 2 mod p is a square.
1
5, 37, 73, 101, 109, 197, 257, 577, 601, 641, 677, 727, 1601, 1801, 2593, 3137, 3389, 3457, 4057, 4357, 5477, 8101, 8837, 10369, 14401, 14407, 16901, 17957, 18253, 18433, 20809, 21317, 22501, 25601, 30977, 33857, 37447, 42437, 44101, 47629, 47653, 50177
OFFSET
1,1
LINKS
EXAMPLE
The order of 2 mod 601 is 25, which is a square, so 601 is a term.
PROG
(PARI)
{ forprime (p=3, 10^6,
r = znorder(Mod(2, p));
if ( issquare(r), print1(p, ", ") );
); }
(Magma) [NthPrime(n): n in [2..6275] | IsSquare(Modorder(2, NthPrime(n)))]; // Bruno Berselli, Jun 08 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt, Jun 03 2012
STATUS
approved