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.

Showing 1-2 of 2 results.

A374335 a(n) is the denominator of x(n) = (16*x(n-1) + (120*n^2 - 89*n + 16)/(512*n^4 - 1024*n^3 + 712*n^2 - 206*n + 21)) mod 1, with x(0) = 0.

Original entry on oeis.org

1, 15, 4095, 765765, 111035925, 78058255275, 24536311574775, 81926744348173725, 154923473562396513975, 154923473562396513975, 595232293160786606325, 76784965817741472215925, 321191512015612578279214275, 3146713243216956429401462252175, 342991743510648250804759385487075
Offset: 0

Views

Author

Paolo Xausa, Jul 06 2024

Keywords

Comments

See A374334 for details and links.

Crossrefs

Cf. A374333, A374334 (numerators), A374581, A374608.

Programs

  • Mathematica
    Block[{n = 0}, Denominator[NestList[Mod[16*# + (120*(++n)^2 - 89*n + 16)/(512*n^4 - 1024*n^3 + 712*n^2 - 206*n + 21), 1] &, 0, 20]]]

A374332 a(n) is the numerator of x(n) = (2*x(n-1) + 1/n) mod 1, with x(0) = 0.

Original entry on oeis.org

0, 0, 1, 1, 11, 1, 7, 64, 289, 1007, 44, 338, 163, 3505, 8297, 44488, 27221, 823117, 993287, 20403983, 26327699, 27713369, 27650353, 315868349, 2488325579, 6016553239, 1399433807, 3562923992, 9142117861, 275160597119, 268889538733, 3968532770473, 114095155444597
Offset: 0

Views

Author

Paolo Xausa, Jul 06 2024

Keywords

Comments

A constant alpha, defined as alpha = Sum_{n >= 1} p(n)/(q(n)*b^n), is b-normal if and only if the associated sequence, defined by x(0) = 0 and x(n) = (b*x(n-1) + p(n)/q(n)) mod 1, is equidistributed in the unit interval.
The present sequence gives the numerators of the associated sequence for alpha = log(2) (where b = 2). See Bailey and Borwein (2005), p. 505 (first example of Theorem 3).
Denominators are given by A374333.

Crossrefs

Cf. A002162, A374333 (denominators), A374334, A374336.

Programs

  • Mathematica
    Block[{n = 0}, Numerator[NestList[Mod[2*# + 1/++n, 1] &, 0, 50]]]
  • PARI
    x(n) = if (n==0, 0, 2*x(n-1) + 1/n);
    a(n) = numerator(frac(x(n))); \\ Michel Marcus, Jul 13 2024
  • Python
    from fractions import Fraction
    from itertools import count, islice
    def A374332_gen(): # generator of terms
        a = Fraction(0,1)
        for n in count(1):
            yield a.numerator
            a = (2*a+Fraction(1,n)) % 1
    A374332_list = list(islice(A374332_gen(),20)) # Chai Wah Wu, Jul 13 2024
    
Showing 1-2 of 2 results.