A297777 Number of distinct runs in base-9 digits of n.

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, 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, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 3, 3, 3, 3

Offset

1,9

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

6643 in base-9: 1,0,1,0,1; five runs, of which 2 are distinct, so that a(6643) = 2.

Mathematica

b = 9; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
Table[s[n], {n, 1, 200}]

Crossrefs

Cf. A043561 (number of runs, not necessarily distinct), A297770.

Sequence in context: A043560 A276034 A111626 * A043536 A043561 A297778

Adjacent sequences: A297774 A297775 A297776 * A297778 A297779 A297780

Keyword

nonn,base,easy

Author

Clark Kimberling, Jan 29 2018

Status

approved