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.

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A153690 Greatest number m such that the fractional part of (11/10)^A153686(n) <= 1/m.

Original entry on oeis.org

10, 4, 3, 18, 253, 58, 618, 484, 6009, 6767, 21386, 697723, 634293, 189959, 4186162, 31102351
Offset: 1

Views

Author

Hieronymus Fischer, Jan 06 2009

Keywords

Examples

			a(4) = 18 since 1/19 < fract((11/10)^A153686(4)) = fract((11/10)^17) = 0.05447... <= 1/18.

Crossrefs

Cf. A153662, A153670, A153678, A153686, A154130, A153698, A153706, A153714, A153722.

Formula

a(n) = floor(1/fract((11/10)^A153686(n))), where fract(x) = x - floor(x).

Extensions

a(14)-a(16) from Jinyuan Wang, Mar 03 2020

A154131 Numbers n such that the fractional part of (4/3)^n is less than 1/n.

Original entry on oeis.org

1, 4, 17, 1738, 1739, 12863, 15705, 109705, 174894, 289047, 720429, 2087694, 2087695, 4475944, 6968999
Offset: 1

Views

Author

Hieronymus Fischer, Jan 11 2009

Keywords

Comments

Numbers n such that fract((4/3)^n) < 1/n, where fract(x) = x - floor(x).
The next term is greater than 3*10^8.

Examples

			a(3)=17 since fract((4/3)^17) = 0.03273... < 1/17, but fract((4/3)^k) >= 1/k for 5 <= k <= 16.

Crossrefs

Cf. A153662, A153670, A153702, A137994, A154139, A154147.
Cf. A002379, A064628.

Programs

  • Mathematica
    Select[Range[1000], N[FractionalPart[(4/3)^#], 100] < (1/#) &] (* G. C. Greubel, Sep 02 2016 *)
  • PARI
    isok(n) = frac((4/3)^n) < 1/n; \\ Michel Marcus, Sep 03 2016

Extensions

a(10)-a(15) from Robert Gerbicz, Nov 21 2010
Previous Showing 21-22 of 22 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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