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.

Previous Showing 11-13 of 13 results.

A317908 Number of decimal places to which the n-th convergent of the continued fraction expansion of Khintchine's constant matches the correct value.

Original entry on oeis.org

0, -1, 1, 2, 2, 3, 3, 4, 4, 6, 5, 8, 8, 9, 11, 13, 12, 14, 15, 16, 16, 16, 18, 21, 21, 23, 24, 24, 25, 25, 26, 27, 28, 29, 30, 30, 32, 32, 33, 33, 36, 35, 36, 37, 37, 38, 39, 39, 40, 41, 42, 42, 43, 44, 45, 44, 46, 47, 48, 48, 49, 50, 51, 54, 55, 56, 56, 58, 58, 60
Offset: 1

Views

Author

A.H.M. Smeets, Aug 10 2018

Keywords

Comments

Decimal expansion of Khintchine's constant in A002210.
For the similar case of the number of correct decimal digits of Pi see A084407.
For the similar case of the number of correct decimal digits of log(2) see A317558.
For the number of correct binary places see A317907.

Examples

			   n   convergent     decimal expansion    a(n)
  ==  =============  ====================  ====
   1     2 / 1       2.0                     0
   2     3 / 1       3.0                    -1
   3     8 / 3       2.66...                 1
   4    43 / 16      2.687...                2
   5    51 / 19      2.684...                2
   6    94 / 35      2.6857...               3
   7   239 / 89      2.6853...               3
   8   333 / 124     2.68548...              4
   9   572 / 213     2.68544...              4
  10  2049 / 763     2.6854521...            6
  oo  lim = A002210  2.685452001065306...   --
		

Crossrefs

Programs

  • Python
    i,cf = 0,[]
    while i <= 20100:
        c = A002211(i)
        cf,i = cf+[c],i+1
    p0,p1,q0,q1,i,base = cf[0],1,1,0,1,10
    while i <= 20100:
        p0,p1,q0,q1,i = cf[i]*p0+p1,p0,cf[i]*q0+q1,q0,i+1
    a0 = p0//q0
    p0 = p0-a0*q0
    i,p0,dd = 0,p0*base,[a0]
    while i < 21000:
        d,p0,i = p0//q0,(p0%q0)*base,i+1
        dd = dd+[d]
    n,pn0,pn1,qn0,qn1 = 1,a0,1,1,0
    while n <= 20000:
        p,q = pn0,qn0
        if p//q != a0:
            print(n,"- manual!")
        else:
            i,p,di = 0,(p%q)*base,a0
            while di == dd[i]:
                i,di,p = i+1,p//q,(p%q)*base
            print(n,i-1)
        n,pn0,pn1,qn0,qn1 = n+1,cf[n]*pn0+pn1,pn0,cf[n]*qn0+qn1,qn0

Formula

Limit_{n -> oo} (a(n)/n) = 2*log(A086702)/log(10) = 2*A100199/log(10) = 2*A240995.

A247039 Decimal expansion of the analog of Lévy's constant in case of the nearest integer continued fraction of -1/2

Original entry on oeis.org

5, 5, 2, 4, 3, 0, 7, 9, 7, 0, 2, 5, 0, 9, 2, 8, 9, 6, 0, 8, 6, 2, 7, 0, 5, 8, 7, 5, 4, 4, 0, 8, 2, 9, 3, 7, 7, 5, 6, 3, 1, 0, 2, 9, 0, 3, 3, 2, 8, 4, 1, 9, 2, 3, 7, 0, 3, 4, 7, 0, 2, 5, 0, 5, 5, 7, 9, 7, 8, 2, 3, 6, 5, 8, 1, 3, 2, 0, 0, 3, 8, 5, 7, 7, 4, 3, 5, 8, 4, 8, 0, 2, 9, 6, 7, 7, 5, 7, 9, 6
Offset: 1

Views

Author

Jean-François Alcover, Sep 10 2014

Keywords

Examples

			5.524307970250928960862705875440829377563102903328419237...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Sections 1.8 Khinchin-Lévy constants p. 62.

Crossrefs

Cf. A086702.

Programs

  • Mathematica
    RealDigits[Exp[Pi^2/(12*Log[GoldenRatio])], 10, 100] // First

Formula

exp(Pi^2/(12*log(phi))), where phi is the golden ratio (1+sqrt(5))/2.

A275696 Decimal expansion of e^(3*Zeta(3)/(4*log(2))).

Original entry on oeis.org

3, 6, 7, 1, 6, 8, 6, 7, 0, 7, 4, 3, 0, 0, 6, 4, 5, 0, 0, 7, 8, 0, 6, 1, 4, 1, 4, 9, 9, 0, 9, 9, 7, 8, 2, 7, 4, 6, 6, 1, 5, 9, 3, 1, 8, 3, 5, 4, 8, 9, 6, 8, 2, 7, 0, 3, 4, 6, 8, 0, 0, 1, 1, 9, 7, 0, 5, 2, 1, 6, 5, 6, 6, 8, 9, 8, 3, 4, 8, 0, 0, 3, 6, 1, 5, 7, 3, 6, 6, 2, 5, 0, 1, 4, 5, 1, 1, 6, 2, 3
Offset: 1

Views

Author

Terry D. Grant, Aug 05 2016

Keywords

Examples

			3.67168670743006450078...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Exp[3*(Zeta[3]/(4*Log[2]))],10,100]
  • PARI
    exp(3*(zeta(3)/(4*log(2)))) \\ G. C. Greubel, Mar 23 2017

Formula

Equals e^(3*Zeta(3)/(4*log(2))) = A001113^(A275689).
Previous Showing 11-13 of 13 results.