A238950 - OEIS

A238950

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

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

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OFFSET

1,6

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..1000

S.-H. Cha, E. G. DuCasse, and L. V. Quintas, Graph Invariants Based on the Divides Relation and Ordered by Prime Signatures, arXiv:1405.5283 [math.NT], 2014 (see 11th line in Table 1).

FORMULA

a(n) = A062799(n)-A238951(n). - Eq. (2.37) [Cha] - R. J. Mathar, May 27 2017

MAPLE

read("transforms") :

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

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