OFFSET
1,2
COMMENTS
Conjecture: The sequence only has 61 terms as listed.
We have checked this extension of the conjecture in A242425 for n up to 10^7.
LINKS
Zhi-Wei Sun, Table of n, a(n) for n = 1..61
EXAMPLE
a(5) = 5 since none of 1^2*2 = 2, 1^2*3 = 3, 2^2*2 = 8 and 2^2*3 = 12 is congruent to 1 modulo 5.
MATHEMATICA
r[k_, n_]:=r[k, n]=PowerMod[k^2, -1, n]
m=0; Do[Do[If[GCD[k, n]==1&&PrimeQ[r[k, n]], Goto[aa]], {k, 1, Sqrt[n-1]}]; m=m+1; Print[m, " ", n]; Label[aa]; Continue, {n, 1, 2000}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zhi-Wei Sun, May 14 2014
STATUS
approved