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 A033651 #30 Jul 08 2025 19:54:19
%S A033651 9,18,99,198,1089,10890,20691,40293,79497,158994,658845,1207701,
%T A033651 2284722,4559544,9019098,17928207,88211178,175322466,839546037,
%U A033651 1570191975,7362102726,13634115363,49985258994,99970517988,188942025987,978462275868,1847034540747,9317488848228
%N A033651 Trajectory of 9 under map x->x + (x-with-digits-reversed).
%C A033651 Trajectories of 27, 36, 45, 54, 63, 72, 81, 90, ..., merge into this sequence. - _Robert G. Wilson v_, Dec 16 2005.
%H A033651 Alois P. Heinz, <a href="/A033651/b033651.txt">Table of n, a(n) for n = 0..1000</a> (first 251 terms from Reinhard Zumkeller)
%H A033651 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a>
%p A033651 a:= proc(n) option remember; `if`(n=0, 9, (h-> h+ (s->
%p A033651 parse(cat(s[-i]$i=1..length(s))))(""||h))(a(n-1)))
%p A033651 end:
%p A033651 seq(a(n), n=0..40); # _Alois P. Heinz_, Jun 18 2014
%t A033651 NestList[ # + FromDigits@Reverse@IntegerDigits@# &, 9, 26] (* _Robert G. Wilson v_ *)
%o A033651 (Haskell)
%o A033651 a063051 n = a063051_list !! n
%o A033651 a063051_list = iterate a056964 879 -- _Reinhard Zumkeller_, Sep 22 2011
%Y A033651 Cf. A006960, A001127, A033648, A033649, A033650.
%Y A033651 Cf. A056964, A004086.
%Y A033651 Row n=9 of A243238.
%Y A033651 Partial sums of A112296.
%K A033651 nonn,base
%O A033651 0,1
%A A033651 _N. J. A. Sloane_