von Mangoldt function times 2

(*start*)
c = 0;
Table[Limit[
  Zeta[s]^2/Zeta[2 s - 1]*
   Total[1/Divisors[n]^(s - 1)*MoebiusMu[Divisors[n]]], s -> 1], {n,
  2, 132}]
ListLinePlot[Accumulate[%]]
(*end*)

{Log[4], Log[9], Log[4], Log[25], 0, Log[49], Log[4], Log[9], 0,
 Log[121], 0, Log[169], 0, 0, Log[4], Log[289], 0, Log[361], 0, 0, 0,
 Log[529]}