This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A285525 The indices that mark the beginning of four consecutive equal terms in A285524. 2
 13, 38, 63, 85, 110, 135, 160, 185, 210, 232, 257, 282, 307, 332, 354, 379, 404, 429, 454, 479, 501, 526, 551, 576, 601, 626, 648, 673, 698, 723, 748, 770, 795, 820, 845, 870, 895, 917, 942, 967, 992 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Davis, Sarah A. Nelson, T. Kyle Petersen, Bridget E. Tenner, The pinnacle set of a permutation, arXiv:1704.05494 [math.CO], 2017. MATHEMATICA b[n_] := b[n] = MaximalBy[Table[{d, d! (d+1)! 2^(n - 2d - 1) StirlingS2[n - d, d + 1]}, {d, 1, n/2}], Last][[All, 1]] // Min; A285524 = Table[b[n], {n, 4, 1000}]; Position[If[Length[#] == 4, Join[{0}, Rest[#]], #]& /@ Split[A285524] // Flatten, 0] + 3 // Flatten (* Jean-François Alcover, Feb 23 2019 *) PROG (PARI) half(n) = if (n % 2, n\2, n/2 - 1); a285524(n) = {v = vector(half(n), d, d!*(d + 1)!*(2^(n-2*d-1)*stirling(n-d, d+1, 2))); w = vecsort(v, , 1); w[#w]; } lista(nn) = {v = vector(nn, n, a285524(n+3)); for (k=1, #v-4, if ((v[k] == v[k+1]) && (v[k] == v[k+2]) && (v[k] == v[k+3]), print1(k+3, ", ")); ); } CROSSREFS Cf. A285524, A285526. Sequence in context: A244185 A044090 A044471 * A209991 A299055 A158647 Adjacent sequences:  A285522 A285523 A285524 * A285526 A285527 A285528 KEYWORD nonn,more AUTHOR Michel Marcus, Apr 20 2017 STATUS approved

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 14 22:42 EST 2019. Contains 329987 sequences. (Running on oeis4.)