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A238950
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The number of arcs from even to odd level vertices in divisor lattice D(n).
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4
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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
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1,6
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LINKS
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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).
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FORMULA
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a(n) = A062799(n)-A238951(n). - Eq. (2.37) [Cha] - R. J. Mathar, May 27 2017
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MAPLE
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read("transforms") :
omega := [seq(A001221(n), n=1..1000)] :
ones := [seq(1, n=1..1000)] :
a062799 := DIRICHLET(ones, omega) ;
for n from 1 do
a238951 := floor(op(n, a062799)/2) ;
a238950 := op(n, a062799)-floor(op(n, a062799)/2) ;
printf("%d %d\n", n, a238950) ;
end do: # R. J. Mathar, May 28 2017
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CROSSREFS
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Cf. A038548.
Sequence in context: A116933 A354060 A194448 * A088433 A335434 A348379
Adjacent sequences: A238947 A238948 A238949 * A238951 A238952 A238953
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KEYWORD
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nonn
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AUTHOR
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Sung-Hyuk Cha, Mar 07 2014
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STATUS
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approved
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