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A159712 Number of permutations of 1..n arranged in a circle with exactly 4 local maxima. 2
0, 0, 0, 0, 0, 0, 0, 0, 2176, 71424, 1372160, 20252672, 255040512, 2891180032, 30447656960, 303926476800, 2914762424320, 27113686958080, 246327423270912, 2196784154673152, 19305427103907840, 167673167523348480, 1442534103145512960, 12315082531044065280 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,9
LINKS
FORMULA
G.f.: -128*(34560*x^7 -146880*x^6 +173712*x^5 -97304*x^4 +29808*x^3 -5120*x^2 +462*x-17)*x^8 / ((8*x-1)^2 *(6*x-1)^3 *(4*x-1)^4 *(2*x-1)^5). - Alois P. Heinz, Oct 26 2015
MATHEMATICA
CoefficientList[Series[-128*(34560*x^7 -146880*x^6 +173712*x^5 -97304*x^4 +29808*x^3 -5120*x^2 +462*x-17)*x^8 / ((8*x-1)^2 *(6*x-1)^3 *(4*x-1)^4 *(2*x-1)^5), {x, 0, 50}], x] (* G. C. Greubel, Jun 02 2018 *)
PROG
(PARI) concat(vector(8), Vec(-128*(34560*x^7 -146880*x^6 +173712*x^5 -97304*x^4 +29808*x^3 -5120*x^2 +462*x-17)*x^8 / ((8*x-1)^2 *(6*x-1)^3 *(4*x-1)^4 *(2*x-1)^5) + O(x^100))) \\ Altug Alkan, Oct 26 2015
CROSSREFS
Column k=4 of A263789.
Sequence in context: A283346 A252348 A252522 * A186917 A185801 A170776
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Apr 20 2009
EXTENSIONS
a(16)-a(23) from Alois P. Heinz, Oct 26 2015
STATUS
approved

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Last modified February 24 22:04 EST 2024. Contains 370307 sequences. (Running on oeis4.)