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A280581 a(n) = the product of divisors of sum of divisors of n. 3

%I

%S 1,3,8,7,36,1728,64,225,13,5832,1728,21952,196,331776,331776,31,5832,

%T 1521,8000,3111696,32768,10077696,331776,46656000000,31,3111696,

%U 2560000,9834496,810000,139314069504,32768,250047,254803968,8503056,254803968,8281,1444

%N a(n) = the product of divisors of sum of divisors of n.

%C a(n) < A007955(n) for numbers n in A219364.

%C a(n) | A007955(n) for numbers n in A219363.

%C A007955(n) | a(n) for numbers n in A219362.

%C n | a(n) for numbers n in A175200.

%H Antti Karttunen, <a href="/A280581/b280581.txt">Table of n, a(n) for n = 1..1024</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%F a(n) = A007955(A000203(n)).

%e For n = 5; a(n) = product of divisors of sigma(5) = 1*2*3*6 = 36.

%t Table[Times @@ Divisors@ DivisorSigma[1, n], {n, 37}] (* _Michael De Vlieger_, Jan 06 2017 *)

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

%o (PARI) a(n) = my(k = 1); fordiv(sigma(n), d, k*=d); k; \\ _Michel Marcus_, Jan 06 2017

%Y Cf. A000203, A007955, A219362, A219363, A219364, A280582.

%K nonn

%O 1,2

%A _Jaroslav Krizek_, Jan 05 2017

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Last modified July 6 23:01 EDT 2020. Contains 335484 sequences. (Running on oeis4.)