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 A118620 #13 Oct 09 2020 15:51:10 %S A118620 1,46,109,946,694,541,190,136,676,721,172,316,658,901,154,496,739,982, %T A118620 334,478,919,964,514,460,109,946,694,541,190,136,676,721,172,316,658, %U A118620 901,154,496,739,982,334,478,919,964,514,460,109,946,694,541,190,136,676,721,172 %N A118620 Start with 1 and repeatedly reverse the digits and add 45 to get the next term. %C A118620 After 2 steps enters a cycle of length 22. %H A118620 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki. %H A118620 <a href="/index/Rec#order_22">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1). %t A118620 NestList[IntegerReverse[#]+45&,1,60] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Oct 09 2020 *) %Y A118620 Cf. A117828, A117816, A117817. %K A118620 base,nonn,easy %O A118620 1,2 %A A118620 Luc Stevens (lms022(AT)yahoo.com), May 08 2006 %E A118620 New a(5)=a(27)=a(49)=694 inserted by _Georg Fischer_, Jul 17 2020