OFFSET
1,2
COMMENTS
phi(n) is the number of totatives of n (A000010).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Sum_{i=1..n} A029940(i).
MAPLE
A029940:= [seq(mul(numtheory:-phi(d), d=numtheory:-divisors(n)), n=1..100)]:
ListTools:-PartialSums(A029940); # Robert Israel, Jan 11 2017
MATHEMATICA
Accumulate@ Array[Product[EulerPhi@ d, {d, Divisors@ #}] &, 47] (* Michael De Vlieger, Dec 27 2016 *)
PROG
(Magma) [&+[&*[EulerPhi(d): d in Divisors(k)]: k in [1..n]]: n in [1..100]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Dec 27 2016
STATUS
approved