OFFSET
1,1
COMMENTS
EXAMPLE
Since 3^5-1 = 242 and 2^5-1 = 31 are relatively prime, a(5) = 3.
MATHEMATICA
Table[k = 1; While[! CoprimeQ[3^n - 1, k^n - 1], k++]; k, {n, 59}] (* Michael De Vlieger, Jan 27 2016 *)
PROG
(Sage)
def min_k(n):
g, k=2, 0
while g!=1:
k=k+1
g=gcd(3^n-1, k^n-1)
return k
print([min_k(n) for n in [1..60]])
(PARI) a(n) = {k=1; while( gcd(3^n-1, k^n-1)!=1, k++); k; }
CROSSREFS
KEYWORD
nonn
AUTHOR
Tom Edgar, Jan 25 2016
STATUS
approved