A281025 Partial sums of A066570.

1, 3, 6, 14, 19, 163, 170, 554, 716, 19916, 19927, 1264087, 1264100, 5779940, 7237940, 17559860, 17559877, 75264356677, 75264356696, 353956196696, 355036399736, 1254282070136, 1254282070159, 16687983940438159, 16687983940813159, 17351136747929959, 17351143890496999

Offset: 1

Author

Jaroslav Krizek, Jan 14 2017

Keywords

• nonn

Crossrefs

Cf. A066570(n) = the product of cototatives of n.

Programs

Maple

ListTools:-PartialSums([seq(A066570(n), n=1..27)]); # Peter Luschny, Nov 02 2017

Mathematica

Table[Times @@ Select[Range[1, n], !CoprimeQ[#, n]&], {n, 1, 26}] // Accumulate (* Jean-François Alcover, Nov 02 2017 *)

Formula

a(n) = Sum_{i=1..n} A066570(i).

Extensions

Edited by Peter Luschny, Nov 02 2017