OFFSET
1,2
FORMULA
If prime(n)-1=3k then a(n)=k otherwise a(n)=prime(n)-1.
EXAMPLE
a(4)=2 for residues of x^3 (mod 7=prime(4)) are 1 and 6;
a(3)=4 for residues of x^3 (mod 5=prime(3)) are 1, 2, 3, 4.
CROSSREFS
KEYWORD
nonn
AUTHOR
Carmine Suriano, Apr 22 2014
STATUS
approved