Sum of the primitive roots of n (mod n).
0, 1, 2, 3, 0, 5, 1, 0, 7, 0, 1, 0, 0, 8, 0, 0, 0, 16, 0, 0, 0, 12, 1, 0, 0, 0, 21, 0, 0, 0, 30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 0, 0, 24, 1, 0, 6, 0, 0, 0, 0, 48, 0, 0, 0, 0, 1, 0, 0, 30, 0, 0, 0, 0, 66, 0, 0, 0, 70, 0, 0, 0, 0, 0, 0, 0, 78, 0, 63, 0, 1, 0
1
The n that produce 1 are all primes in A088179. The n that produce n-1 are A078330 plus 1, 2, 4, and 6. The n that produce n/2+1 are twice the primes in A088179. The n that produce n/2-1 are twice the primes in A078330. If n is prime and n-1 is not squarefree, then s(n) = 0 and n is in A049092.
T. D. Noe, Plot of 1000 terms
T. D. Noe, Table of 1000 terms
Eric W. Weinstein, MathWorld: Primitive Root
(Mma) Table[Mod[Plus @@ PrimitiveRootList[n], n], {n, 100}]
Cf. A049092, A078330, A088179, A121380.
nonn
T. D. Noe, Apr 02 2015