OFFSET
1,2
COMMENTS
If p is prime, a(p) = Sum_{d|p} d^(phi(p/d) - 1) = 1^(p-2) + p^0 = 1 + 1 = 2.
EXAMPLE
a(14) = Sum_{d|14} d^(phi(14/d) - 1) = 1^(6-1) + 2^(6-1) + 7^(1-1) + 14^(1-1) = 1 + 32 + 1 + 1 = 35.
MATHEMATICA
Table[Sum[k^(EulerPhi[n/k^(1 - Ceiling[n/k] + Floor[n/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