A037889 - OEIS

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

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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)) ;