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A178020 Number of permutations of 3 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/5)] (5-way heap) 0
1, 10, 200, 13440, 2097900, 442030200, 257134170000, 122150707608000, 111415794466080000, 163780469919918720000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..10.

CROSSREFS

Simple 2-way heap A056971

Sequence in context: A156275 A036362 A051262 * A041183 A210168 A041180

Adjacent sequences:  A178017 A178018 A178019 * A178021 A178022 A178023

KEYWORD

nonn

AUTHOR

R. H. Hardin May 17 2010

STATUS

approved

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Last modified October 30 07:54 EDT 2014. Contains 248796 sequences.