Number of distinct primes among the squares mod prime(n).

0, 0, 0, 1, 2, 1, 2, 4, 3, 4, 4, 3, 5, 6, 5, 8, 8, 6, 7, 7, 9, 9, 11, 10, 11, 12, 13, 15, 12, 11, 16, 15, 13, 19, 16, 16, 15, 11, 15, 21, 20, 15, 16, 21, 24, 19, 26, 24, 24, 19, 21, 20, 24, 26, 26, 23, 27, 25, 22, 25, 33, 30, 33, 27, 29, 37, 36, 33, 36, 33, 36

1

This is the highest component of the plot of A132213.

T. D. Noe, Plot of 1000 terms

T. D. Noe, Table of 1000 terms

(Mma) Table[s = Union[Mod[Range[n]^2, n]]; Length[Select[s, PrimeQ]], {n, Prime[Range[50]]}]

Cf. A132213.

nonn

T. D. Noe, Jun 24 2015