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 A096841 #11 Jul 01 2019 05:44:22
%S A096841 1,2,3,4,5,7,43,146,365,438,443,803,887,2221,4442,6663,8887,87876,
%T A096841 88183,153837,250244,285597,292860,296294,302877,307674,344268,351612,
%U A096841 380718,403398,423260,441821,444443,550238,579038,584438,588974,593163,600363
%N A096841 Numbers n such that sum of divisors of these numbers gives a decimal repdigit.
%H A096841 Giovanni Resta, <a href="/A096841/b096841.txt">Table of n, a(n) for n = 1..365</a>
%e A096841 n=43:sigma[43]=44; regular solutions:repdigit-1=prime.
%t A096841 rd[x_] := Length[Union[IntegerDigits[x]]] Do[s = rd[DivisorSigma[1, n]]; s1 = DivisorSigma[1, n]; If[Equal[s, 1], Print[{n, s1}]; ta[[u]] = n; u = u + 1], {n, 1, 1000000}];ta;DivisorSigma[1, ta]
%t A096841 Select[Range[650000],Length[Union[IntegerDigits[DivisorSigma[1,#]]]]==1&] (* _Harvey P. Dale_, May 11 2019 *)
%Y A096841 Cf. A096503-A096508, A096841-A096846, A000203.
%K A096841 base,nonn
%O A096841 1,2
%A A096841 _Labos Elemer_, Jul 15 2004