A335416 - OEIS

%I #14 Jul 29 2020 06:17:46

%S 5,16,27,17,7,37,679,1343,911,3163,741,10652,793,3310,7027,8263,8381,

%T 1777,114419,27952,18301,47987,1480987,27593,1346549,12821,159847,

%U 92503,1612207,861440,7920089,3251923,544897,15681619,3047987,18092504,1643309,193472

%N a(n) = numerator of Sum_{k=2..A335138(n)} abs(A309229(n, k))/k.

%t nn = 38; f[n_] := n; h[n_] := DivisorSum[n, MoebiusMu[#] # &]; A = Accumulate[Table[Table[h[GCD[n, k]], {k, 1, nn}], {n, 1, nn}]]; B = -Abs[A]; B[[All, 1]] = Table[f[n], {n, 1, nn}]; b = 1 + Total[Sign[1 + Sign[Accumulate[Transpose[B]]]]]; d = Table[Sum[Abs[A[[n, k]]]/k, {k, 2, b[[n]]}], {n, 1, nn}]; Numerator[d]

%Y Cf. A309229, A335138. See A335417 for denominators.

%K nonn,frac

%O 1,1

%A _Mats Granvik_, Jun 09 2020