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 A118530 #9 Oct 27 2015 10:07:19 %S A118530 1,14,54,58,98,102,214,425,537,748,860,81,31,26,75,70,20,15,64,59,108, %T A118530 814,431,147,754,470,87,91,32,36,76,80,21,25,65,69,109,914,432,247, %U A118530 755,570,88,101,114,424,437,747,760,80,21,25,65,69,109,914,432 %N A118530 Start with 1 and repeatedly reverse the digits and add 13 to get the next term. %H A118530 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki. %H A118530 <a href="/index/Rec#order_18">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, 1). %F A118530 After 31 steps enters a cycle of length 18. %t A118530 NestList[FromDigits[Reverse[IntegerDigits[#]]]+13&,1,60] (* _Harvey P. Dale_, Oct 27 2015 *) %Y A118530 Cf. A117828, A117816, A117817. %K A118530 nonn,base %O A118530 1,2 %A A118530 _N. J. A. Sloane_, May 06 2006