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 A043565 #9 Apr 23 2021 21:54:18
%S A043565 1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,
%T A043565 2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,
%U A043565 2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2
%N A043565 Number of runs in base-13 representation of n.
%C A043565 Every positive integers occurs infinitely many times. See A297770 for a guide to related sequences.
%t A043565 b = 13; s[n_] := Length[Split[IntegerDigits[n, b]]];
%t A043565 Table[s[n], {n, 1, 200}]
%Y A043565 Cf. A297781 (number of distinct runs), A297770.
%K A043565 nonn,base
%O A043565 0,14
%A A043565 _Clark Kimberling_