OFFSET
1,4
FORMULA
a(p^k) = p^(k-1) * pi(p^(k-1)), for prime p and k >= 1. - Wesley Ivan Hurt, Jun 26 2024
MATHEMATICA
Table[n*DivisorSum[n, PrimePi[n/#]/# &, PrimeQ[#] &], {n, 100}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Feb 03 2024
STATUS
approved