OFFSET
1,2
FORMULA
G.f.: Sum_{k>=1} prime(k)# * x^prime(k) / (1 - x^prime(k)). - Ilya Gutkovskiy, Sep 10 2021
a(prime(n)) = A002110(n). - Wesley Ivan Hurt, Oct 18 2021
EXAMPLE
a(14) = Sum_{p|14} p # = 2 # + 7 # = 2 + 7*5*3*2 = 212.
MATHEMATICA
Table[Sum[Product[i^(PrimePi[i] - PrimePi[i - 1]), {i, k}] (PrimePi[k] - PrimePi[k - 1]) (1 - Ceiling[n/k] + Floor[n/k]), {k, n}], {n, 60}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Jun 12 2021
STATUS
approved