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%I #9 Aug 26 2022 05:25:46
%S 1,4,5,8,12,20,9,24,14,30,20,40,24,36,36,32,30,56,30,96,33,50,36,120,
%T 32,96,54,72,72,90,33,80,68,84,68,112,60,120,72,180,96,132,60,160,168,
%U 90,68,160,80,128,90,150,84,216,90,216,102,180,120,288
%N a(n) = usigma(sigma(n)), where usigma(n) is the sum of unitary divisors of n (A034448) and sigma(n) is the sum of the divisors (A000203).
%H Nathaniel Johnston, <a href="/A061765/b061765.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A034448(A000203(n)). - _Amiram Eldar_, Aug 26 2022
%t a[n_] := Times @@ (1 + Power @@@ FactorInteger[DivisorSigma[1, n]]); a[1] = 1; Array[a, 100] (* _Amiram Eldar_, Aug 26 2022 *)
%Y Cf. A000203, A034448.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Oct 30 2001
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