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A297775
Number of distinct runs in base-7 digits of n.
3
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, 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, 3, 3, 2, 3, 2, 3, 3, 3, 3, 2, 3, 3, 2, 3, 3, 3, 2, 3
OFFSET
1,7
COMMENTS
Every positive integers occurs infinitely many times. See A297770 for a guide to related sequences.
LINKS
EXAMPLE
1234567 in base-7: 1,3,3,3,1,2,1,5; six runs, of which 4 are distinct, so that a(1234567) = 4.
MATHEMATICA
b = 7; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
Table[s[n], {n, 1, 200}]
CROSSREFS
Cf. A043559 (number of runs, not necessarily distinct), A297770, A043534.
Sequence in context: A043558 A307359 A368860 * A043534 A043559 A083165
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Jan 27 2018
STATUS
approved