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%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_