OFFSET
1,4
FORMULA
a(p^k) = k*p^(k-1), for prime p and k >= 1. - Wesley Ivan Hurt, Jun 26 2024
MATHEMATICA
Table[n*DivisorSum[n, DivisorSigma[0, n/#]/# &, PrimeQ[#] &], {n, 80}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Feb 04 2024
STATUS
approved