%I
%S 0,0,1,1,2,2,4,3,4,5,7,5,7,7,9,9,10,9,12,10,12,14,16,12,14,15,17,17,
%T 19,17,21,18,19,21,23,21,24,24,26,24,26,24,28,26,28,32,34,28,30,30,33,
%U 33,35,33,37,35,37,39,41,35,39,39,41,41,42,42,46,44,46,46,50,43,46,46,48
%N The number of nondivisors k of n, 1 < k < n, for which floor(n/k) is odd.
%C See the illustration in the second link: a(n) is the number of arcs that are intercepted by a vertical line intersecting the abscissa at n.
%C Sum of the differences of the number of divisors of the largest parts and the number of divisors of the smallest parts of the partitions of n into two parts.  _Wesley Ivan Hurt_, Jan 05 2017
%H Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poldiv01.jpg">Illustration of the number of divisors of n</a>
%H Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poldiv03.jpg">Illustration of the number of divisors of n (Another version)</a>
%F a(n) = Sum_{i=1..floor(n/2)} d(ni)  d(i) where d(n) is the number of divisors of n.  _Wesley Ivan Hurt_, Jan 05 2017
%p A177235 := proc(n) local a; a :=0 ; for k from 1 to n1 do if n mod k <> 0 and type(floor(n/k),'odd') then a := a+1 ; end if; end do: a ; end proc:
%p seq(A177235(n),n=1..120) ; # _R. J. Mathar_, May 24 2010
%Y Cf. A000005, A049820.
%K nonn,easy
%O 1,5
%A _Omar E. Pol_, May 23 2010
%E Terms from a(16) onwards from _R. J. Mathar_, May 24 2010
