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 A033899 #12 Feb 03 2025 05:38:57 %S A033899 17,34,68,136,272,499,998,1897,3686,7354,10811,11929,23228,45466, %T A033899 90032,90271,91550,93109,94508,99097,107096,108775,124553,248008, %U A033899 250496,275065,300632,302968,326657,562324,785780,843568,1189256,2314945,3549404 %N A033899 Sort then Add, a(1)=17. %p A033899 A033899 := proc(n) %p A033899 option remember ; %p A033899 if n =1 then %p A033899 17; %p A033899 else %p A033899 A070196(procname(n-1)) ; %p A033899 end if; %p A033899 end proc: %p A033899 seq(A033899(n),n=1..100) ; # _R. J. Mathar_, Feb 03 2025 %t A033899 NestList[FromDigits[Sort[IntegerDigits[#]]]+#&, 17,40] (* _Harvey P. Dale_, Apr 07 2018 *) %Y A033899 Cf. A033860. %K A033899 nonn,base,easy %O A033899 1,1 %A A033899 _N. J. A. Sloane_, _David W. Wilson_