A297775 Number of distinct runs in base-7 digits of n.

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

Clark Kimberling, Table of n, a(n) for n = 1..10000

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

Adjacent sequences: A297772 A297773 A297774 * A297776 A297777 A297778

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 27 2018

Status

approved