A280259 Partial sums of A280258.

1, 3, 6, 11, 36, 45, 766, 876, 3119, 3334, 3632135, 3632532, 482634133, 482654160, 483551083, 485578218, 20923275466219, 20923275553553, 6423296981281554, 6423296990011493, 6423344287548216, 6423345541114343, 1124007151123148794344, 1124007151123185976991

Offset: 1

Author

Jaroslav Krizek, Jan 01 2017

Keywords

• nonn

Crossrefs

Cf. A001783, A280258, A280260.

Programs

Magma

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

Mathematica

Accumulate@ Table[Sum[Times @@ Select[Range@ d, CoprimeQ[#, d] &], {d, Divisors@ n}], {n, 24}] (* Michael De Vlieger, Jan 01 2017 *)

Formula

a(n) = Sum_{i=1..n} A280258(i) where A280258(n) = Sum_{d|n} pxi(d), where pxi(m) is the product of totatives of m (A001783).