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A238957 The number of nodes at even level in divisor lattice in graded colexicographic order. 1
1, 1, 2, 2, 2, 3, 4, 3, 4, 5, 6, 8, 3, 5, 6, 8, 9, 12, 16, 4, 6, 8, 8, 10, 12, 14, 16, 18, 24, 32, 4, 7, 9, 10, 12, 15, 16, 18, 20, 24, 27, 32, 36, 48, 64, 5, 8, 11, 12, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..50.

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

CROSSREFS

Cf. A038548 in graded colexicographic order.

Sequence in context: A055034 A112184 A112213 * A238970 A085755 A241952

Adjacent sequences:  A238954 A238955 A238956 * A238958 A238959 A238960

KEYWORD

nonn

AUTHOR

Sung-Hyuk Cha, Mar 07 2014

STATUS

approved

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Last modified February 22 15:52 EST 2019. Contains 320399 sequences. (Running on oeis4.)