A280086 Partial products of A206032 (Product_{d|n} sigma(d)).

1, 3, 12, 252, 1512, 217728, 1741824, 548674560, 28531077120, 9244068986880, 110928827842560, 3130855237028413440, 43831973318397788160, 25247216631397125980160, 14542396779684744564572160, 142006504553621530673047142400, 2556117081965187552114848563200

Offset: 1

Author

Jaroslav Krizek, Dec 26 2016

Keywords

• nonn

Comments

sigma(n) is the sum of the divisors of n (A000203).

Crossrefs

Cf. A000203, A007429, A206032, A280078 (partial products of A007429), A280085 (partial sums of A206032).

Programs

Magma

[&*[&*[SumOfDivisors(d): d in Divisors(k)]: k in [1..n]]: n in [1..100]]

Mathematica

FoldList[Times[#1, #2] &, Array[Product[DivisorSigma[1, d], {d, Divisors@ #}] &, 17]] (* Michael De Vlieger, Dec 26 2016 *)

Formula

a(n) = Product_{i=1..n} A206032(i).