A280820 Partial sums of A001783.

1, 2, 4, 7, 31, 36, 756, 861, 3101, 3290, 3632090, 3632475, 482634075, 482653380, 483550276, 485577301, 20923275465301, 20923275550386, 6423296981278386, 6423296990008107, 6423344287544107, 6423345537481432, 1124007151123145161432, 1124007151123182343577

Offset: 1

Author

Jaroslav Krizek, Jan 08 2017

Keywords

• nonn

Comments

A001783(n) = the product of totatives of n.

Crossrefs

Cf. A001783, A280821.

Programs

Magma

[&+[&*[h: h in [1..k] | GCD(h,k) eq 1]: k in [1..n]]: n in [1..100]]

Mathematica

Accumulate@ Table[Times @@ Select[Range@ n, CoprimeQ[n, #] &], {n, 24}] (* Michael De Vlieger, Jan 09 2017 *)

Formula

a(n) = Sum_{i=1..n} A001783(i).