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%I #43 Apr 15 2020 02:23:56
%S 1,3,4,6,7,8,12,12,13,14,15,18,18,20,24,24,24,28,30,31,31,32,32,36,38,
%T 39,40,42,42,42,44,48,48,48,54,54,56,56,57,60,60,60,62,63,68,72,72,72,
%U 72,72,74,78,80,80,84,84,84,90,90,90,91,93,96,96,96,96,98,98
%N Values taken by the sigma function A000203, listed with multiplicity and in ascending order.
%C A175192(a(n)) = 1, A054973(a(n)) >= 1. - _Jaroslav Krizek_, Mar 01 2010
%C a(n) is the median of the values of A000203(m) from m=1 to m=2n-1. (This needs confirmation as it relies on the assumption that A000203(n) is always bigger than the median of the values A000203(x) from x=1 to x=n.) - _Chayim Lowen_, May 27 2015
%H T. D. Noe, <a href="/A007609/b007609.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = sigma(A085790(n)). - _Jinyuan Wang_, Apr 15 2020
%p sort(select(`<=`,map(numtheory:-sigma,[$1..1000]),1001)); # _Robert Israel_, Jun 04 2015
%t terms = 68; ClearAll[t]; t[k_] := t[k] = Sort[ Table[ DivisorSigma[1, n], {n, 1, k*terms}]][[1 ;; terms]]; t[k = 2]; While[t[k] != t[k-1], k++]; t[k] (* _Jean-François Alcover_, Nov 21 2012 *)
%t With[{nn=80},Take[Sort[DivisorSigma[1,Range[nn*100]]],nn]] (* _Harvey P. Dale_, Mar 09 2016 *)
%o (PARI) list(lim)=select(k->k<=lim,Set(apply(sigma,[1..lim\1]))) \\ _Charles R Greathouse IV_, Mar 09 2014
%Y Cf. A000203, A002191 (duplicates removed), A007368, A085790.
%K nonn,easy,nice
%O 1,2
%A _Walter Nissen_
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