The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A152503 1/8 of the number of permutations of 3 indistinguishable copies of 1..n with exactly 6 local maxima. 1

%I

%S 0,0,0,925,5134608,7080780596,5503883684118,3175651343215500,

%T 1543855504958661492,676391857775294288488,277604477433374392213008,

%U 109265969423431070616562496,41856404659462959845867172864,15752452465692536904424614273024,5860017184412283112523269770190848

%N 1/8 of the number of permutations of 3 indistinguishable copies of 1..n with exactly 6 local maxima.

%H Andrew Howroyd, <a href="/A152503/b152503.txt">Table of n, a(n) for n = 1..200</a>

%o (PARI) \\ PeaksBySig defined in A334774.

%o a(n) = {PeaksBySig(vector(n,i,3), [5])[1]/8} \\ _Andrew Howroyd_, May 12 2020

%Y Cf. A152499, A334774.

%K nonn

%O 1,4

%A _R. H. Hardin_, Dec 06 2008

%E Terms a(9) and beyond from _Andrew Howroyd_, May 12 2020

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 2 16:17 EST 2021. Contains 349445 sequences. (Running on oeis4.)