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 A033655 #16 Jul 08 2025 19:54:47 %S A033655 19,110,121,242,484,968,1837,9218,17347,91718,173437,907808,1716517, %T A033655 8872688,17735476,85189247,159487405,664272356,1317544822,3602001953, %U A033655 7193004016,13297007933,47267087164 %N A033655 Trajectory of 19 under map x->x + (x-with-digits-reversed). %H A033655 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a> %t A033655 NestList[#+FromDigits[Reverse[IntegerDigits[#]]]&,19,30] (* _Harvey P. Dale_, Jan 24 2015 *) %t A033655 NestList[#+IntegerReverse[#]&,19,30] (* _Harvey P. Dale_, Dec 18 2023 *) %K A033655 nonn,base %O A033655 0,1 %A A033655 _N. J. A. Sloane_