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A297781
Number of distinct runs in base-13 digits of n.
3
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, 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, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2
OFFSET
1,13
COMMENTS
Every positive integers occurs infinitely many times. See A297770 for a guide to related sequences.
LINKS
EXAMPLE
5200468 in base-13: 1,1,0,1,1,0,0; four runs, of which 3 are distinct, so that a(5200468) = 3.
MATHEMATICA
b = 13; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
Table[s[n], {n, 1, 200}]
CROSSREFS
Cf. A043565 (number of runs, not necessarily distinct), A297770.
Sequence in context: A297780 A043564 A043539 * A043565 A043540 A297782
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Feb 03 2018
STATUS
approved