A037884 - OEIS

%I #11 Dec 30 2023 16:50:37

%S 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,

%T 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,

%U 5,2,2,2,2,3,4,5,3,3,3,3,3,4,5,4,4,4,4,4,4,5

%N 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.

%p A037884 := proc(n)

%p     local a,dgs,dgsE ;

%p     a := 0 ;

%p     dgs := convert(n,base,7);

%p     dgsE := sort(dgs) ;

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

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

%p     end do:

%p     a/2 ;

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

%K nonn,base

%O 1,10

%A _Clark Kimberling_

%E Definition swapped with A037875. - _R. J. Mathar_, Oct 19 2015