A037884 a(n)=(1/2)*Sum{|d(i)-e(i)|} where Sum{d(i)*7^i} is the base 7 representation of n and e(i) are the digits d(i) in nondecreasing order.

0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 0, 0, 0, 1, 2, 3, 4, 0, 0, 0, 0, 1, 2, 3, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 0, 0, 1, 2, 3, 4, 5, 1, 1, 1, 2, 3, 4, 5, 2, 2, 2, 2, 3, 4, 5, 3, 3, 3, 3, 3, 4, 5, 4, 4, 4, 4, 4, 4, 5

Offset

1,10

Links

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

Maple

A037884 := proc(n)
    local a, dgs, dgsE ;
    a := 0 ;
    dgs := convert(n, base, 7);
    dgsE := sort(dgs) ;
    for i from 1 to nops(dgs) do
        a := a+ abs(op(i, dgs)-op(i, dgsE)) ;
    end do:
    a/2 ;
end proc: # R. J. Mathar, Oct 19 2015

Crossrefs

Sequence in context: A118022 A181368 A037848 * A347728 A336206 A303534

Adjacent sequences: A037881 A037882 A037883 * A037885 A037886 A037887

Keyword

nonn,base

Author

Clark Kimberling

Extensions

Definition swapped with A037875. - R. J. Mathar, Oct 19 2015

Status

approved