A037889 - OEIS

%I #7 Oct 19 2015 14:18:53

%S 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,

%T 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,

%U 3,2,1,4,3,2,3,2,1,2,1,0,1,0,1,2,1,2,3,2,3,1

%N (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.

%p A037889 := proc(n)

%p     local a,dgs ;

%p     a := 0 ;

%p     dgs := convert(n,base,3);

%p     for i from 1 to nops(dgs) do

%p         a := a+ abs(op(i,dgs)-op(-i,dgs)) ;

%p     end do:

%p     a/2 ;

%p end proc: # _R. J. Mathar_, Oct 19 2015

%K nonn,base

%O 1,6

%A _Clark Kimberling_