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 A118087 #14 Nov 08 2019 11:05:52
%S A118087 1,44,87,121,164,504,448,887,831,181,224,465,607,749,990,142,284,525,
%T A118087 568,908,852,301,146,684,529,968,912,262,305,546,688,929,972,322,266,
%U A118087 705,550,98,132,274,515,558,898,941,192,334,476,717,760,110,54,88,131,174,514,458,897,841,191,234,475,617,759,1000,44
%N A118087 Start with 1 and repeatedly reverse the digits and add 43 to get the next term.
%C A118087 After 1 step enters a cycle of length 63.
%H A118087 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki.
%H A118087 <a href="/index/Rec#order_63">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, 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, 0, 0, 0, 0, 1).
%F A118087 a(n) = 43 + A004086(a(n-1)) for n > 1, a(1) = 1. - _Alois P. Heinz_, Nov 07 2019
%p A118087 a:= proc(n) option remember; `if`(n=1, 1, 43 +(s-> parse(
%p A118087 cat(seq(s[-i], i=1..length(s)))))(cat("", a(n-1))))
%p A118087 end:
%p A118087 seq(a(n), n=1..65); # _Alois P. Heinz_, Nov 07 2019
%Y A118087 Cf. A004086, A117828, A117816, A117817.
%K A118087 base,nonn
%O A118087 1,2
%A A118087 Luc Stevens (lms022(AT)yahoo.com), May 11 2006
%E A118087 a(43)-a(52) corrected and more terms added by _Alois P. Heinz_, Nov 07 2019