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 A362440 #7 Oct 16 2023 11:13:59 %S A362440 841,30,42,54,66,78,90,144,259,45,33,15,9,4,3,1,0 %N A362440 Aliqout sequence starting at 841. %C A362440 This is 841 followed by A008885. Could be further extended backwards, see A070015. %D A362440 GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 92. %t A362440 NestWhileList[DivisorSigma[1,#]-#&,841,#>0&] (* _Paolo Xausa_, Oct 16 2023 *) %Y A362440 Cf. A001065, A008885, A070015. %K A362440 nonn,fini,full %O A362440 1,1 %A A362440 _N. J. A. Sloane_, Apr 22 2023