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 A113466 #16 Jun 10 2021 07:41:21 %S A113466 1,3,3,213,213,1383,3091,8129,943607,943607,19235031,21470685, %T A113466 21470685,21470685,21470685 %N A113466 Least number that begins an n-term arithmetic progression with common difference 2 in which all terms have the same number of divisors. %C A113466 Second column of A113465. Next term is > 6368300000. %e A113466 a(4) = 213 because 213, 215, 217 and 219 each have 4 divisors. %t A113466 Module[{nn=21470695,ds},ds=Table[DivisorSigma[0,n],{n,1,nn,2}];2*Table[ SequencePosition[ds,PadRight[{},k,x_],1],{k,15}][[All,1]]][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* The program will take a long time to run. To generate the first 8 terms of the sequence, change the nn constant to 8200 and the k range from 15 to 8 and the program will run quickly. *) (* _Harvey P. Dale_, Aug 16 2020 *) %Y A113466 Cf. A113457, A113465. %K A113466 nonn,less,hard %O A113466 1,2 %A A113466 _David Wasserman_, Jan 08 2006