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A180068 Number of permutations of 1..n with the sum of squared adjacent differences <= n*(n-1)/2 0
2, 2, 6, 16, 34, 140, 508, 2100, 9386, 44398, 214410, 1103178, 6002116, 33772692, 196340714, 1190396084, 7486976948 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..18.

CROSSREFS

Sequence in context: A336633 A001464 A067136 * A034439 A230825 A060165

Adjacent sequences:  A180065 A180066 A180067 * A180069 A180070 A180071

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 09 2010

EXTENSIONS

a(17)-a(18) from Donovan Johnson, Oct 11 2010

STATUS

approved

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Last modified March 8 08:16 EST 2021. Contains 341942 sequences. (Running on oeis4.)