A037864 a(n)=(number of digits <=2)-(number of digits >2) in base 5 representation of n.

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

Offset

0,5

Links

Table of n, a(n) for n=0..81.

Maple

A037864 := proc(n)
    a := 0 ;
    dgs := convert(n, base, 5);
    for i from 1 to nops(dgs) do
        if op(i, dgs)<=2 then
            a := a+1 ;
        else
            a := a-1 ;
        end if;
    end do:
    a ;
end proc: # R. J. Mathar, Oct 16 2015

Mathematica

nd5[n_]:=Module[{idn5=IntegerDigits[n, 5], a}, a=Count[idn5, _?(#<=2&)]; 2a-Length[idn5]]; Array[nd5, 90] (* Harvey P. Dale, Oct 13 2011 *)

Crossrefs

Sequence in context: A004541 A178045 A321300 * A285635 A181674 A181676

Adjacent sequences: A037861 A037862 A037863 * A037865 A037866 A037867

Keyword

base,sign

Author

Clark Kimberling

Status

approved