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 A143090 #15 Nov 01 2024 12:45:01 %S A143090 12,16,15,9,4,3,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, %T A143090 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, %U A143090 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 %N A143090 Aliquot sequence starting at 12. %H A143090 Dominika Závacká, Cristina Dalfó, and Miquel Angel Fiol, <a href="https://ceur-ws.org/Vol-3792/paper19.pdf">Integer sequences from k-iterated line digraphs</a>, CEUR: Proc. 24th Conf. Info. Tech. - Appl. and Theory (ITAT 2024) Vol 3792, 156-161. See p. 161, Table 2. %F A143090 a(n+1) = A001065(a(n)). - _R. J. Mathar_, Oct 11 2017 %t A143090 NestList[If[#>0,DivisorSigma[1, #]-#,0]&,12,100] (* _Paolo Xausa_, Oct 16 2023 *) %Y A143090 Cf. A001065. %K A143090 nonn,easy %O A143090 0,1 %A A143090 _N. J. A. Sloane_, Nov 30 2008