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A178021
Number of permutations of 3 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/6)] (6-way heap)
0
1, 10, 250, 22500, 2788800, 1002405600, 359463283200, 326108342112000, 257963213378304000
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OFFSET
1,2
LINKS
Table of n, a(n) for n=1..9.
CROSSREFS
Simple 2-way heap
A056971
Sequence in context:
A108792
A265854
A128013
*
A134262
A240289
A001536
Adjacent sequences:
A178018
A178019
A178020
*
A178022
A178023
A178024
KEYWORD
nonn
AUTHOR
R. H. Hardin
May 17 2010
STATUS
approved
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Last modified May 28 12:54 EDT 2024. Contains 372913 sequences. (Running on oeis4.)
