A180073 - OEIS

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A180073

Number of permutations of 1..n with the sum of squared adjacent differences < (n-1)*n*(n+1)/6.

1

0, 2, 12, 56, 344, 2486, 19936, 179772, 1800566, 19867748, 238718608, 3105919304, 43474755484, 652732780048, 10446585803476, 177631436657888

(list; graph; refs; listen; history; text; internal format)

OFFSET

2,2

LINKS

Table of n, a(n) for n=2..17.

CROSSREFS

Cf. A000292, A180072.

Sequence in context: A105487 A098453 A256150 * A363402 A067125 A177782

Adjacent sequences: A180070 A180071 A180072 * A180074 A180075 A180076

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 09 2010

EXTENSIONS

a(14) from Donovan Johnson, Oct 11 2010

a(15)-a(17) from Martin Ehrenstein, Nov 16 2023

STATUS

approved