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 1-3 of 3 results.

A374334 a(n) is the numerator 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

0, 2, 1076, 188663, 106894973, 32442016954, 16143697977964, 43667396600461261, 82482175187690988496, 80845733759021750791, 209616749220518838502, 48891577015658186678698, 60882892596227901210360094, 108196850082040258114673507582, 189145139720511629801253759599798
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 (with b = 2) for alpha = Pi. See Bailey and Borwein (2005), p. 505 (second example of Theorem 3). In the same paper, on p. 513, they conjecture that, for n >= 1, y(n) = floor(16*x(n)) = A062964(n+1). See also Bailey and Crandall (2001), p. 176.
Denominators are given by A374335.

Crossrefs

Programs

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

A374580 a(n) is the numerator of (120*n^2 + 151*n + 47)/(512*n^4 + 1024*n^3 + 712*n^2 + 194*n + 15).

Original entry on oeis.org

47, 106, 829, 316, 857, 3802, 5273, 776, 1787, 11126, 4519, 16228, 19139, 1486, 25681, 29312, 3687, 37294, 8329, 15412, 51067, 56138, 20483, 2680, 72791, 8758, 85093, 91604, 6557, 105346, 112577, 40016, 127759, 27142, 15989, 152332, 161003, 56638, 35813, 188456
Offset: 0

Views

Author

Paolo Xausa, Jul 12 2024

Keywords

Comments

See Bailey and Crandall (2001), section 5 (pp. 183-184) for a derivation of this rational polynomial.
Denominators are given by A374581.

Crossrefs

Cf. A000796, A001025, A374334, A374581 (denominators), A374607.

Programs

  • Mathematica
    A374580[n_] := Numerator[(120*n^2 + 151*n + 47)/(512*n^4 + 1024*n^3 + 712*n^2 + 194*n + 15)];
    Array[A374580, 50, 0]
  • Python
    from math import gcd
    def A374580(n): return (lambda p,q: p//gcd(p,q))(n*(120*n + 151) + 47,n*(n*(n*(512*n + 1024) + 712) + 194) + 15) # Chai Wah Wu, Jul 14 2024

Formula

Sum_{n >= 0} (1/16^n)*a(n)/A374581(n) = A000796. See Bailey and Crandall (2001), eq. 5-2, p. 184.

A374608 a(n) is the denominator of (1134*n^3 + 2097*n^2 + 1188*n + 193)/(10368*n^4 + 20736*n^3 + 14112*n^2 + 3744*n + 320).

Original entry on oeis.org

320, 12320, 396032, 24035, 4222400, 2360960, 18446720, 511313, 54017600, 21079520, 125864960, 5660830, 252900032, 86027840, 458015360, 18690490, 768084800, 242991008, 1213963520, 23415035, 1830488000, 553679360, 2656476032, 49394345, 3734726720, 1095728480, 5112020480
Offset: 0

Views

Author

Paolo Xausa, Jul 13 2024

Keywords

Comments

See Bailey and Crandall (2001), section 5 (pp. 183-185) for a derivation of this rational polynomial.
Numerators are given by A374607.

Crossrefs

Cf. A000796, A010482, A089357, A374335, A374581, A374607 (numerators).

Programs

  • Mathematica
    A374608[n_] := Denominator[(1134*n^3 + 2097*n^2 + 1188*n + 193)/(10368*n^4 + 20736*n^3 + 14112*n^2 + 3744*n + 320)];
    Array[A374608, 50, 0]
  • Python
    from math import gcd
    def A374608(n): return (q:=n*(n*(n*(324*n + 648) + 441) + 117) + 10<<5)//gcd(n*(n*(1134*n + 2097) + 1188) + 193,q) # Chai Wah Wu, Jul 14 2024

Formula

sqrt(27)*(Sum_{n >= 0} (1/64^n)*A374607(n)/a(n)) = A000796. See Bailey and Crandall (2001), p. 185.
Showing 1-3 of 3 results.