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 A063850 #16 Jun 08 2025 15:20:08
%S A063850 1,11,21,1211,3112,132112,311322,232122,421311,14123113,41141223,
%T A063850 24312213,32142321,23322114,32232114,23322114,32232114,23322114,
%U A063850 32232114,23322114,32232114,23322114,32232114,23322114,32232114
%N A063850 Say what you see in previous term, reporting total number for each digit encountered.
%C A063850 The digits of each term a(n) are a permutation of those of the corresponding term A005151(n). - _Chayim Lowen_, Jul 16 2015
%F A063850 After a while sequence has period 2.
%e A063850 To get the term after 311322, we say: two 3's, two 1's, two 2's, so 232122.
%t A063850 deldup[ lst_ ] := Module[ {i, s}, s={}; For[ i=1, i<=Length[ lst ], i++, If[ !MemberQ[ s, lst[ [ i ] ] ], AppendTo[ s, lst[ [ i ] ] ] ] ]; s ]; next[ term_ ] := FromDigits[ Flatten[ ({Count[ IntegerDigits[ term ], # ], #}&)/@deldup[ IntegerDigits[ term ] ] ] ]
%o A063850 (Python)
%o A063850 from collections import Counter; s = '1'
%o A063850 for _ in range(25):
%o A063850 print(s, end = ', '); d = Counter(s); s = ''
%o A063850 for k, v in d.items(): s += str(v) + k # _Ya-Ping Lu_, Jun 06 2025
%Y A063850 A variant of A005150, A005151, etc.
%K A063850 base,easy,nonn
%O A063850 0,2
%A A063850 _N. J. A. Sloane_, Aug 25 2001
%E A063850 Corrected and extended by _Dean Hickerson_, Aug 27 2001