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A227013 Floor(M(g(n-1)+1,..,g(n))), where M = harmonic mean and g(n) = n^4. 4
1, 6, 40, 152, 413, 920, 1792, 3173, 5232, 8160, 12173, 17512, 24440, 33245, 44240, 57760, 74165, 93840, 117192, 144653, 176680, 213752, 256373, 305072, 360400, 422933, 493272, 572040, 659885, 757480, 865520, 984725, 1115840, 1259632, 1416893 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A227012.

LINKS

Table of n, a(n) for n=1..35.

Index entries for linear recurrences with constant coefficients, signature (4,-6,5,-5,6,-4,1).

FORMULA

a(n) = 47/9 + 14*n + (41*n^2)/3 + 6*n^3 + n^4 - (2/9)Cos(2*n*pi/3) (conjectured).

a(n) = 4*a(n-1) - 6*a(n-2) + 5*a(n-3) - 5*a(n-4) + 6*a(n-5) - 4*a(n-6) + a(n-7) for n > 2 (conjectured).

G.f.:  (-1 - 2*x - 22*x^2 - 23*x^3 - 20*x^4 - 4*x^5 + 2*x^6 - 3*x^7 + x^8)/((-1 + x)^5 (1 + x + x^2)) (conjectured).

EXAMPLE

a(1) = floor(1/(1/1)) = 1, a(2) = floor(15/(1/2 + 1/3 + ... + 1/16) = 6.

MATHEMATICA

z = 30; f[x_] := f[x] = 1/x; g[n_] := g[n] = n^4; s[n_] := s[n] = Sum[f[k], {k, g[n - 1] + 1, g[n]}]; v[n_] := v[n] = (g[n] - g[n - 1])/s[n]; Table[Floor[v[n]], {n, 1, z}]

CROSSREFS

Cf. A227012.

Sequence in context: A089207 A318169 A027777 * A073773 A001919 A005553

Adjacent sequences:  A227010 A227011 A227012 * A227014 A227015 A227016

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Jul 01 2013

EXTENSIONS

Extended by Ray Chandler, Jul 15 2015

STATUS

approved

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Last modified April 22 08:50 EDT 2019. Contains 322329 sequences. (Running on oeis4.)