OFFSET
1,6
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Sum_{prime p|n} A062799(n/p) = Sum_{prime p|n} Sum_{prime q|(n/p)} A000005(n/p/q). - Max Alekseyev, Aug 11 2016
MATHEMATICA
a[n_] := DivisorSum[n, PrimeNu[#] * PrimeNu[n/#] &]; Array[a, 100] (* Amiram Eldar, May 20 2022 *)
PROG
(PARI) for(n=1, 100, print1(sumdiv(n, d, omega(n/d)*omega(d)), ", "))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, May 12 2002
STATUS
approved