OFFSET
1,2
COMMENTS
a(n) is always integer because lambda(n) divides phi(n), and phi(n) divides J_2(n).
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
jordanTotient[n_, k_: 1] := DivisorSum[n, #^k*MoebiusMu[n/#] &] /; (n > 0) && IntegerQ[n]; Table[jordanTotient[n, 2]/CarmichaelLambda[n], {n, 100}] (* T. D. Noe, Dec 11 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Enrique Pérez Herrero, Dec 11 2012
STATUS
approved