cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A227014 a(n) = floor(M(g(n-1)+1,..,g(n))), where M = harmonic mean and g(n) = n^5.

Original entry on oeis.org

1, 10, 104, 543, 1883, 5102, 11717, 23906, 44626, 77735, 128110, 201769, 305989, 449428, 642243, 896212, 1224852, 1643541, 2169636, 2822595, 3624095, 4598154, 5771249, 7172438, 8833478, 10788947, 13076362, 15736301, 18812521, 22352080
Offset: 1

Views

Author

Clark Kimberling, Jul 01 2013

Keywords

Comments

See A227012. It is conjectured that A227014 is a linear recurrence sequence with signature (5,-10,10,-5,1,...Z...,1,-5,-10,-10,-1,0,0), where ...Z... represents a string of 138 zeros; has been confirmed for a(1), a(2),..., a(150000).

Examples

			a(1) = floor(1/(1/1)) = 1.
a(2) = floor(31/(1/2 + 1/3 + ... + 1/32)) = 10.
		

Crossrefs

Programs

  • Mathematica
    Clear[g]; g[n_] := N[n^5, 100]; a = {1}; Do[AppendTo[a, Floor[(#2 - #1 + 1)/(HarmonicNumber[#2]-HarmonicNumber[#1 - 1])] &[g[k - 1] + 1, g[k]]], {k, 2, 200}]; a (* Peter J. C. Moses, Jul 05 2012 *)
    (* confirm generating function *)
    p = {1, -4, 5, 9, 54, 117, 117, 122, 118, 122, 118, 122, 118, 122,
       118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118,
       122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122,
       118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118,
       122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122,
       119, 117, 129, 107, 134, 106, 134, 106, 134, 106, 134, 106, 134,
       106, 134, 106, 134, 107, 129, 117, 119, 122, 118, 122, 118, 122,
       118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118,
       122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122,
       118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118,
       122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122, 118, 122,
       117, 126, 113, 113, 64, 5, 1};
    q = {0, 0, 1, -5, 10, -10, 5, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 5, -10, 10, -5,
        1}; gf = Fold[x #1 + #2 &, 0, p]/Fold[x #1 + #2 &, 0, q]; CoefficientList[Series[Factor[gf], {x, 0, 100}], x] (* Peter J. C. Moses, Jul 08 2012 *)