OFFSET
1,4
COMMENTS
The number of units u in Z/nZ such that Phi(1,u) or Phi(2,u) is a unit is given by A058026.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (terms to 1000 from Jordan Lenchitz)
MAPLE
m:=3; T:=[]: for n from 2 to 1000 do S:={}: for a from 0 to n-1 do if gcd(a, n)=1 and gcd(cyclotomic(m, a), n)=1 then S:={op(S), a}: fi: od: T:=[op(T), nops(S)]: od: print(m, T):
MATHEMATICA
Table[Count[Map[Cyclotomic[3, #] &, Select[Range@ n, CoprimeQ[#, n] &]], u_ /; CoprimeQ[u, n]], {n, 72}] (* Michael De Vlieger, Jul 11 2017 *)
PROG
(PARI) g(n)=sum(k=0, n-1, gcd(k, n)==1 && gcd(polcyclo(3, k), n)==1)
a(n)=my(f=factor(n)); prod(i=1, #f~, g(f[i, 1]^f[i, 2])) \\ Charles R Greathouse IV, Jul 06 2017
CROSSREFS
KEYWORD
nonn,mult,easy
AUTHOR
Jordan Lenchitz, Michael Mueller, Tristan Phillips, Madison Wellen, Eric Jovinelly, Joshua Harrington, Jul 06 2017
STATUS
approved