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 A118295 #17 Jan 08 2024 10:56:18
%S A118295 20,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,
%T A118295 7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,
%U A118295 3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10
%N A118295 Start with 20 and repeatedly reverse the digits and add 1 to get the next term.
%C A118295 After 1 step enters a cycle of length 9.
%H A118295 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki.
%H A118295 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,1).
%e A118295 After a(9) = 10 we get a(10) = (reversed digits of a(9)) + 1 = 01 + 1 = 2. - _David A. Corneth_, Jan 08 2024
%t A118295 PadRight[{20},100,Range[2,10]] (* _Paolo Xausa_, Jan 08 2024 *)
%o A118295 (PARI) a(n) = if(n == 1, return(20)); return(((n-1)%9) + 2) \\ _David A. Corneth_, Jan 08 2024
%Y A118295 Cf. A118551.
%Y A118295 Essentially the same as A117230.
%K A118295 nonn,easy,base
%O A118295 1,1
%A A118295 Luc Stevens (lms022(AT)yahoo.com), May 14 2006