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A178019
Number of permutations of 3 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/4)] (4-way heap)
0
1, 7, 170, 8870, 976720, 216658080, 99152064000, 32300260082400
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OFFSET
1,2
LINKS
Table of n, a(n) for n=1..8.
CROSSREFS
Simple 2-way heap
A056971
Sequence in context:
A172027
A113562
A157203
*
A337676
A266306
A332117
Adjacent sequences:
A178016
A178017
A178018
*
A178020
A178021
A178022
KEYWORD
nonn
AUTHOR
R. H. Hardin
May 17 2010
STATUS
approved
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Last modified April 25 13:12 EDT 2024. Contains 371969 sequences. (Running on oeis4.)