This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A235710 #26 May 24 2025 09:39:18
%S A235710 14,124,194,1324,1994,13324,133324,1130324,1333324,13333324,62496048,
%T A235710 133333324,92782317392,7453083061400,657119364560000,671701040192960,
%U A235710 199999999999999994,1333333333333333324
%N A235710 Composite numbers k such that sum of the proper divisors of k is a power of 10.
%C A235710 Composite numbers k such that reversal(sigma(k)-k) = 1.
%C A235710 If k is prime, then sum of the proper divisors of k is 10^0.
%C A235710 Terms include 2*(10^A089675(k)-3) and 4*(10^A055557(k)-7)/3 for all k >= 1.
%e A235710 sigma(14)-14 = 1+2+7 = 10, sigma(124)-124 = 1+2+4+31+62 = 100.
%t A235710 r[n_]:=FromDigits[Reverse[IntegerDigits[n]]]; Do[If[!PrimeQ[n]&& r[DivisorSigma[1,n]-n]==1, Print[n]],{n, 200000000}]
%Y A235710 Cf. A000203, A004086, A055557, A089675.
%K A235710 nonn,base,more
%O A235710 1,1
%A A235710 _Farideh Firoozbakht_, Mar 17 2014
%E A235710 a(13) from _Giovanni Resta_, Mar 21 2014
%E A235710 Edited and a(14)-a(18) added by _Max Alekseyev_, May 24 2025