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 A033897 #16 Feb 03 2025 05:38:19 %S A033897 13,26,52,77,154,299,598,1187,2365,4721,5968,11657,23224,45458,90016, %T A033897 90185,91774,106553,120109,121238,233476,466943,811612,922880,945769, %U A033897 1402568,1527136,2650703,2674270,2898947,5377846,8834624,11179312 %N A033897 Sort then Add, a(1)=13. %p A033897 A033897 := proc(n) %p A033897 option remember ; %p A033897 if n =1 then %p A033897 13; %p A033897 else %p A033897 A070196(procname(n-1)) ; %p A033897 end if; %p A033897 end proc: %p A033897 seq(A033897(n),n=1..100) ; # _R. J. Mathar_, Feb 03 2025 %t A033897 NestList[#+FromDigits[Sort[IntegerDigits[#]]]&,13,40] (* _Harvey P. Dale_, Sep 09 2012 *) %Y A033897 Cf. A033860. %K A033897 nonn,base,easy %O A033897 1,1 %A A033897 _N. J. A. Sloane_, _David W. Wilson_