[math-fun] New sequence

With all this discussion of square roots I engendered, I decided to invesitigate the number of square roots of 1 mod n. This turned out to be given by A060594, which is a multiplicative sequence with a(2^n) = 1 if n = 0; 1 if n = 1; 2 if n = 2; 4 if n >= 3. a(p^n) = 1 if n = 0; 2 if n >= 1. This shows that every modulus m has 2^k square roots of 1 for some k. With a little thought, I was able to convince myself that the least modulus m with 2^k square roots of 1 is 1 if k = 0; 3 if k = 1; 4*p[n-1]# if k >= 2. where p[n] is the nth prime and p# is the primorial of p.