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%I #27 Jul 22 2021 07:59:41
%S 1,69,258,270,276,609,639,2391,2556,2931,3409,3678,3679,4291,5092,
%T 6937,8251,10231,12087,12931,15480,16387,20850,22644,22893,24369,
%U 26145,26442,27846,28764,29880,29958,30823,31812,32658,34207,34758
%N Numbers k such that the digits of sigma(k) are a permutation of those of k, in base 10.
%C There is some m > 1 such that a(n) > m*n for all n > 1. This follows from the positive density of numbers k such that sigma(k)/k > 10. - _Charles R Greathouse IV_, Sep 07 2012
%H V. Raman, <a href="/A115920/b115920.txt">Table of n, a(n) for n = 1..10000</a>
%e sigma(10231) = 11032, sigma(31812) = 81312.
%t Select[Range[35000],Sort[IntegerDigits[#]]==Sort[ IntegerDigits[ DivisorSigma[ 1,#]]]&] (* _Harvey P. Dale_, May 09 2013 *)
%o (Python)
%o from sympy import divisor_sigma
%o A115920_list = [n for n in range(1,10**4) if sorted(str(divisor_sigma(n))) == sorted(str(n))] # _Chai Wah Wu_, Dec 13 2015
%o (PARI) isok(n) = vecsort(digits(n)) == vecsort(digits(sigma(n))); \\ _Michel Marcus_, Dec 13 2015 and May 27 2018
%Y Cf. A000203, A114065, A115921, A175795.
%K nonn,base
%O 1,2
%A _Giovanni Resta_, Feb 06 2006
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