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%I #14 Nov 08 2017 05:11:40
%S 1,3,2,7,6,12,2,15,13,18,12,28,14,24,24,31,18,39,20,42,2,6,24,60,31,
%T 42,40,56,30,72,2,63,48,54,48,91,38,60,56,90,42,96,44,84,78,72,48,124,
%U 57,93,72,98,54,120,72,120,80,90,60,168,62,96,104,127,84,12,68,126,96,12
%N a(n) = the smallest number m such that sigma(n) = m^k for any k >= 1 (sigma = A000203).
%C a(n) = A000203(n) ^ (1 / A175432(n)).
%C a(n) = A052410(A000203(n)). - _Antti Karttunen_, Nov 06 2017
%H Antti Karttunen, <a href="/A175433/b175433.txt">Table of n, a(n) for n = 1..16384</a>
%e For n = 7, a(7) = 2 because sigma(7) = 8 = 2^3.
%t Array[#^(1/Apply[GCD, FactorInteger[#][[All, -1]]]) &@ DivisorSigma[1, #] &, 105] (* _Michael De Vlieger_, Nov 05 2017 *)
%o (PARI) A175433(n) = { my(s=sigma(n),m); ispower(s,,&m); if(m,m,s); }; \\ _Antti Karttunen_, Nov 05 2017
%Y Cf. A000203, A052410, A175432.
%K nonn
%O 1,2
%A _Jaroslav Krizek_, May 10 2010
%E Extended by _Ray Chandler_, Aug 20 2010
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