Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #4 Feb 03 2018 16:38:12
%S 1,1,1,1,1,1,1,1,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,
%T 2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,
%U 2,1,2,2,2,2,2,2,2,2,2,1,2,2,3,3,3,3
%N Number of distinct runs in base-9 digits of n.
%C Every positive integers occurs infinitely many times. See A297770 for a guide to related sequences.
%H Clark Kimberling, <a href="/A297777/b297777.txt">Table of n, a(n) for n = 1..10000</a>
%e 6643 in base-9: 1,0,1,0,1; five runs, of which 2 are distinct, so that a(6643) = 2.
%t b = 9; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
%t Table[s[n], {n, 1, 200}]
%Y Cf. A043561 (number of runs, not necessarily distinct), A297770.
%K nonn,base,easy
%O 1,9
%A _Clark Kimberling_, Jan 29 2018