login
Partial products of A007429 (Sum_{d|n} sigma(d)).
2

%I #11 Sep 08 2022 08:46:18

%S 1,4,20,220,1540,30800,277200,7207200,129729600,3632428800,

%T 47221574400,2597186592000,38957798880000,1402480759680000,

%U 49086826588800000,2797949115561600000,53161033195670400000,3827594390088268800000,80379482191853644800000

%N Partial products of A007429 (Sum_{d|n} sigma(d)).

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

%F a(n) = Product_{i=1..n} A007429(i).

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

%Y Cf. A000203, A280075 (partial products of A211776), A280077 (partial sums of A007429).

%K nonn

%O 1,2

%A _Jaroslav Krizek_, Dec 25 2016