OFFSET
1,16
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
17830144 in base-16: 1,1,0,1,1,0,0; four runs, of which 3 are distinct, so that a(17830144) = 3.
MATHEMATICA
b = 16; s[n_] := Length[Union[Split[IntegerDigits[n, b]]]]
Table[s[n], {n, 1, 200}]
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Clark Kimberling, Feb 03 2018
STATUS
approved