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

1,2

Comments

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

Links

Table of n, a(n) for n=1..24.

Formula

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

Mathematica

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

Prog

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

Crossrefs

Cf. A001783, A280821.

Sequence in context: A102119 A102121 A102120 * A280377 A102122 A102123

Adjacent sequences: A280817 A280818 A280819 * A280821 A280822 A280823

Keyword

nonn

Author

Jaroslav Krizek, Jan 08 2017

Status

approved