%I #25 Jun 28 2017 01:00:25

%S 0,1,1,1,1,2,1,2,1,2,1,4,1,2,2,2,1,4,1,4,2,2,1,5,1,2,2,4,1,6,1,3,2,2,

%T 2,6,1,2,2,5,1,6,1,4,4,2,1,7,1,4,2,4,1,5,2,5,2,2,1,10,1,2,4,3,2,6,1,4,

%U 2,6,1,9,1,2,4,4,2,6,1,7,2,2,1,10,2,2

%N The number of arcs from even to odd level vertices in divisor lattice D(n).

%H R. J. Mathar, <a href="/A238950/b238950.txt">Table of n, a(n) for n = 1..1000</a>

%H S.-H. Cha, E. G. DuCasse, and L. V. Quintas, <a href="http://arxiv.org/abs/1405.5283">Graph Invariants Based on the Divides Relation and Ordered by Prime Signatures</a>, arXiv:1405.5283 [math.NT], 2014 (see 11th line in Table 1).

%F a(n) = A062799(n)-A238951(n). - Eq. (2.37) [Cha] - _R. J. Mathar_, May 27 2017

%p read("transforms") :

%p omega := [seq(A001221(n), n=1..1000)] :

%p ones := [seq(1,n=1..1000)] :

%p a062799 := DIRICHLET(ones,omega) ;

%p for n from 1 do

%p a238951 := floor(op(n,a062799)/2) ;

%p a238950 := op(n,a062799)-floor(op(n,a062799)/2) ;

%p printf("%d %d\n",n,a238950) ;

%p end do: # _R. J. Mathar_, May 28 2017

%Y Cf. A038548.

%K nonn

%O 1,6

%A _Sung-Hyuk Cha_, Mar 07 2014