A037866 a(n)=(number of digits <=3)-(number of digits >3) in base 7 representation of n.

1, 1, 1, -1, -1, -1, 2, 2, 2, 2, 0, 0, 0, 2, 2, 2, 2, 0, 0, 0, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, -2, -2, -2, 0, 0, 0, 0, -2, -2, -2, 0, 0, 0, 0, -2, -2, -2, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, 1

Offset

0,7

Links

Table of n, a(n) for n=0..83.

Mathematica

d37[n_]:=Module[{d=IntegerDigits[n, 7]}, Count[d, _?(#<4&)]-Count[d, _?(#>3&)]]; Array[d37, 90, 0] (* Harvey P. Dale, Jun 28 2022 *)

Crossrefs

Sequence in context: A338505 A037867 A122879 * A333181 A306216 A238451

Adjacent sequences: A037863 A037864 A037865 * A037867 A037868 A037869

Keyword

base,sign

Author

Clark Kimberling

Status

approved