OFFSET
1,4
COMMENTS
a(p) = Sum_{p|p} (p/p)^lcm(p,p/p) = 1^p = 1 for primes p.
EXAMPLE
a(10) = Sum_{p|10} (10/p)^lcm(p,10/p) = 5^lcm(2,5) + 2^lcm(5,2) = 5^10 + 2^ 10 = 9766649.
MATHEMATICA
Table[Sum[(n/k)^LCM[k, n/k] (PrimePi[k] - PrimePi[k - 1]) (1 - Ceiling[n/k] + Floor[n/k]), {k, n}], {n, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Jun 13 2021
STATUS
approved