A037889 (1/2)*Sum{|d(i)-e(i)|} where Sum{d(i)*3^i} is base 3 representation of n and e(i) are digits d(i) in reverse order.

0, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 2, 1, 0, 2, 1, 0, 1, 0, 1, 2, 1, 2, 3, 2, 3, 2, 1, 2, 1, 0, 1, 2, 1, 2, 3, 2, 3, 2, 1, 2, 1, 0, 1, 2, 1, 0, 3, 2, 1, 4, 3, 2, 3, 2, 1, 2, 1, 0, 3, 2, 1, 4, 3, 2, 3, 2, 1, 2, 1, 0, 1, 0, 1, 2, 1, 2, 3, 2, 3, 1

Offset

1,6

Links

Table of n, a(n) for n=1..90.

Maple

A037889 := proc(n)
    local a, dgs ;
    a := 0 ;
    dgs := convert(n, base, 3);
    for i from 1 to nops(dgs) do
        a := a+ abs(op(i, dgs)-op(-i, dgs)) ;
    end do:
    a/2 ;
end proc: # R. J. Mathar, Oct 19 2015

Crossrefs

Sequence in context: A073368 A321756 A258141 * A339872 A280269 A321894

Adjacent sequences: A037886 A037887 A037888 * A037890 A037891 A037892

Keyword

nonn,base

Author

Clark Kimberling

Status

approved