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 A297775 #7 Feb 02 2018 03:53:28
%S A297775 1,1,1,1,1,1,2,1,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,1,2,2,
%T A297775 2,2,2,2,2,1,2,2,2,2,2,2,2,1,2,2,3,3,3,3,3,2,1,2,2,2,2,2,3,2,2,3,3,3,
%U A297775 3,3,2,3,2,3,3,3,3,2,3,3,2,3,3,3,2,3
%N A297775 Number of distinct runs in base-7 digits of n.
%C A297775 Every positive integers occurs infinitely many times. See A297770 for a guide to related sequences.
%H A297775 Clark Kimberling, <a href="/A297775/b297775.txt">Table of n, a(n) for n = 1..10000</a>
%e A297775 1234567 in base-7: 1,3,3,3,1,2,1,5; six runs, of which 4 are distinct, so that a(1234567) = 4.
%t A297775 b = 7; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
%t A297775 Table[s[n], {n, 1, 200}]
%Y A297775 Cf. A043559 (number of runs, not necessarily distinct), A297770, A043534.
%K A297775 nonn,base,easy
%O A297775 1,7
%A A297775 _Clark Kimberling_, Jan 27 2018