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 A130651 1/16 the number of permutations of 0..n having exactly 3 maxima. 1
 0, 0, 0, 0, 1, 17, 180, 1536, 11616, 81552, 545536, 3532544, 22368000, 139434240, 859634688, 5258379264, 31986270208, 193796182016, 1170829049856, 7059331547136 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS FORMULA Conjecture: a(n) = 2^(n-8)*(3^(n+1) - 2^(n+2)*n + 2*n^2 - 3). - Vaclav Kotesovec, Nov 29 2012 Empirical g.f.: -x^4*(3*x-1) / ((2*x-1)^3*(4*x-1)^2*(6*x-1)). - Colin Barker, Dec 06 2014 Empirical: a(n) = A000487(n+1)/16. - R. J. Mathar, Mar 01 2015 CROSSREFS Cf. A100575. Sequence in context: A042985 A125405 A342198 * A142214 A066521 A055904 Adjacent sequences:  A130648 A130649 A130650 * A130652 A130653 A130654 KEYWORD nonn AUTHOR R. H. Hardin, Aug 11 2007 STATUS approved

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Last modified May 18 13:16 EDT 2021. Contains 343995 sequences. (Running on oeis4.)