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A226440 Number of permutations of 1..n with fewer than 7 interior elements having values lying between the values of their neighbors 1
1, 2, 6, 24, 120, 720, 5040, 40320, 362878, 3627778, 39830282, 475089392, 6094561180, 83333937940, 1205398303180, 18331873363480, 291706615484450, 4838414115229430, 83404373736108502, 1490681666580459304 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 7 of A226441

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..206

EXAMPLE

Some solutions for n=7

..2....2....2....1....7....2....6....4....2....2....7....1....1....4....6....4

..5....3....1....7....4....3....7....2....1....7....3....3....5....3....3....5

..3....7....6....2....5....6....2....1....5....6....5....4....4....2....2....6

..4....1....4....4....2....7....1....5....6....4....6....6....7....1....4....2

..7....4....3....3....3....4....4....3....4....5....2....7....3....5....7....3

..1....6....5....5....6....1....5....6....3....3....1....2....2....6....1....7

..6....5....7....6....1....5....3....7....7....1....4....5....6....7....5....1

CROSSREFS

Sequence in context: A054873 A324075 A193936 * A248841 A072132 A230231

Adjacent sequences:  A226437 A226438 A226439 * A226441 A226442 A226443

KEYWORD

nonn

AUTHOR

R. H. Hardin Jun 06 2013

STATUS

approved

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Last modified June 25 06:10 EDT 2019. Contains 324347 sequences. (Running on oeis4.)