A280260 Partial products of A280258.

1, 2, 6, 30, 750, 6750, 4866750, 535342500, 1200773227500, 258166243912500, 936833924075923912500, 371923067858141793262500, 178151744952881559857748513262500, 3567844996171358999271129475108087500, 3200082237501003827703259262202371164762500

Offset: 1

Author

Jaroslav Krizek, Jan 01 2017

Keywords

• nonn

Comments

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

Crossrefs

Cf. A001783, A280258, A280259.

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

FoldList[#1 #2 &, #] &@ Table[Sum[Times @@ Select[Range@ d, CoprimeQ[#, d] &], {d, Divisors@ n}], {n, 15}] (* Michael De Vlieger, Jan 01 2017 *)

Formula

a(n) = Product_{i=1..n} A280258(i).