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%I #4 Feb 04 2018 12:42:36
%S 1,1,1,1,1,1,1,1,1,1,1,1,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,
%T 2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,
%U 2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2
%N Number of distinct runs in base-13 digits of n.
%C Every positive integers occurs infinitely many times. See A297770 for a guide to related sequences.
%H Clark Kimberling, <a href="/A297781/b297781.txt">Table of n, a(n) for n = 1..10000</a>
%e 5200468 in base-13: 1,1,0,1,1,0,0; four runs, of which 3 are distinct, so that a(5200468) = 3.
%t b = 13; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
%t Table[s[n], {n, 1, 200}]
%Y Cf. A043565 (number of runs, not necessarily distinct), A297770.
%K nonn,base,easy
%O 1,13
%A _Clark Kimberling_, Feb 03 2018