OFFSET
1,2
COMMENTS
Inverse Mobius transform of A062355.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Sum_{d|n} phi(d)*tau(d).
a(n) = Sum_{k=1..n} tau(n/gcd(n, k)).
a(n) = Sum_{d|n} d*uphi(n/d), where uphi() = A047994(). - Vladeta Jovovic, Mar 16 2004
MAPLE
A062949 := proc(n) add(numtheory[phi](d)*numtheory[tau](d), d=numtheory[divisors](n)) ; end proc: # R. J. Mathar, Feb 09 2011
MATHEMATICA
f[p_, e_] := ((e+1)*p^(e+1)-(e+2)*p^e+1)/(p-1); a[1] = 1; a[n_] := Times @@ (f @@@ FactorInteger[n]); Array[a, 60] (* Amiram Eldar, Jul 31 2019 *)
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
Vladeta Jovovic, Jul 21 2001
STATUS
approved