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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A034164 Related to triple factorial numbers 2*A034000(n+1).

Original entry on oeis.org

1, 5, 30, 198, 1386, 10098, 75735, 580635, 4528953, 35819901, 286559208, 2314516680, 18846778680, 154543585176, 1274984577702, 10574872085646, 88123934047050, 737458184920050, 6194648753328420, 52212039492339540, 441429061162507020, 3742550735942994300
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( (1 -3*x -(1-9*x)^(1/3))/(3*x)^2 )); // G. C. Greubel, Sep 17 2019
    
  • Maple
    seq(coeff(series((1-3*x-(1-9*x)^(1/3))/(3*x)^2, x, n+2), x, n), n = 0..32); # G. C. Greubel, Sep 17 2019
  • Mathematica
    CoefficientList[Series[ HypergeometricPFQ[{1, 5/3}, {3}, 9 x], {x, 0, 20}], x]
    Table[FullSimplify[3^(2*n+1) * Gamma[n+5/3] / ((n+2) * Gamma[2/3] * Gamma[n+2])],{n,0,20}] (* Vaclav Kotesovec, Feb 09 2014 *)
    CoefficientList[Series[(1 -3x -(1-9 x)^(1/3))/(3 x)^2, {x, 0, 30}], x] (* Vincenzo Librandi, Feb 10 2014 *)
  • PARI
    my(x='x+O('x^30)); Vec((1 -3*x -(1-9*x)^(1/3))/(3*x)^2) \\ G. C. Greubel, Sep 17 2019
    
  • Sage
    def A034164_list(prec):
        P. = PowerSeriesRing(QQ, prec)
        return P((1 -3*x -(1-9*x)^(1/3))/(3*x)^2).list()
    A034164_list(30) # G. C. Greubel, Sep 17 2019

Formula

a(n) = 3^n*(3*n+2)!!!/(n+2)!, where (3*n+2)!!! = 2*A034000(n+1).
G.f.: (1 - 3*x - (1-9*x)^(1/3))/(3*x)^2.
G.f.: 2F1( (1, 5/3); 3; 9 x ). - Olivier Gérard, Feb 15 2011
D-finite with recurrence: (n+2)*a(n) - 3*(3*n+2)*a(n-1) = 0. - R. J. Mathar, Oct 29 2012
a(n) = 3^(2*n+1) * Gamma(n+5/3) / ((n+2) * Gamma(2/3) * Gamma(n+2)). - Vaclav Kotesovec, Feb 09 2014
Integral representation as the n-th moment of a positive function on (0,9): a(n) = Integral_{x=0..9} x^n*W(x) dx, n >= 0, where W(x) = (1/18)*9^(1/3)*sqrt(3)*x^(2/3)*(1-x/9)^(1/3)/Pi. This representation is unique as W(x) is the solution of the Hausdorff moment problem. - Karol A. Penson, Nov 07 2015
Sum_{n>=0} 1/a(n) = 15/16 + (27/64)*(Pi*sqrt(3)/3 - log(3)). - Amiram Eldar, Dec 02 2022
a(n) ~ 3^(2*n+1) * n^(-4/3) / Gamma(2/3). - Amiram Eldar, Aug 19 2025

A284867 Decimal expansion of Ai(0), where Ai is the Airy function of the first kind.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Apr 04 2017

Keywords

Examples

			0.35502805388781723926006318600418317639797917419917724058332651030081...
		

References

  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 56, page 559.

Crossrefs

Cf. A096714, A096715, A269892, A269893, A073006 (Gamma(2/3)), A284868 (Ai'(0)).

Programs

Formula

Ai(0) = 1/(3^(2/3)*Gamma(2/3)).

A030652 Continued fraction for Gamma(2/3).

Original entry on oeis.org

1, 2, 1, 4, 1, 2, 8, 1, 1, 4, 4, 1, 6, 12, 1, 5, 1, 1, 1, 3, 2, 1, 1, 1, 18, 9, 1, 42, 1, 1, 2, 1, 1, 10, 3, 2, 4, 6, 2, 11, 1, 1, 8, 65, 9, 4, 1, 11, 2, 3, 1, 4, 3, 1, 2, 1, 2, 1, 5, 1, 1, 1, 2, 1, 14, 1, 5, 1, 6, 2, 7, 1, 29, 1, 1, 1, 3, 1, 2, 1, 26, 1, 1, 7, 13, 1, 2, 2, 8, 3, 4, 2, 2, 2
Offset: 0

Views

Author

Paolo Dominici (pl.dm(AT)libero.it)

Keywords

Examples

			1.354117939426400416945288028... = 1 + 1/(2 + 1/(1 + 1/(4 + 1/(1 + ...)))). - _Harry J. Smith_, May 14 2009
		

Crossrefs

Cf. A030651, A073006 (decimal expansion).

Programs

  • Mathematica
    ContinuedFraction[Gamma[2/3],100] (* Harvey P. Dale, Sep 05 2021 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 5200); x=contfrac(gamma(2/3)); for (n=1, 5000, write("b030652.txt", n-1, " ", x[n])); } \\ Harry J. Smith, May 14 2009

Formula

Note that 3*GAMMA(1/3)*GAMMA(2/3) = 2*Pi*sqrt(3).

Extensions

Offset changed by Andrew Howroyd, Aug 03 2024

A204067 Decimal expansion of the Fresnel Integral, Integral_{x >= 0} cos(x^3) dx.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jan 10 2013

Keywords

Examples

			0.7733429420779898501961016...
		

Crossrefs

Programs

  • Maple
    evalf(int(cos(x^3),x=0..infinity),120); # Muniru A Asiru, Sep 26 2018
  • Mathematica
    RealDigits[Gamma[1/3]/(2*Sqrt[3]), 10, 120][[1]] (* Amiram Eldar, May 26 2023 *)
  • PARI
    Pi/(3*gamma(2/3)) \\ Gheorghe Coserea, Sep 26 2018
    
  • PARI
    intnum(x=[0, -2/3], [oo, I], cos(x)/x^(2/3))/3 \\ Gheorghe Coserea, Sep 26 2018

Formula

Equals Pi/(3*Gamma(2/3)) = A019670 / A073006.
Equals Gamma(1/3)/(2*sqrt(3)) = A073005 / A010469. - Amiram Eldar, May 26 2023

A290570 Decimal expansion of Integral_{0..Pi/2} dtheta/(cos(theta)^3 + sin(theta)^3)^(2/3).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Aug 07 2017

Keywords

Examples

			1.766638750285449957313689499648438702571868538202557530126905241835453...
		

References

  • Oscar S. Adams, Elliptic Functions Applied to Conformal World Maps, Special Publication No. 112 of the U.S. Coast and Geodetic Survey, 1925. See constant K p. 9 and previous pages.

Crossrefs

Cf. A073005 (Gamma(1/3)), A073006 (Gamma(2/3)), A197374 (Beta(1/3,1/3)).

Programs

  • Mathematica
    RealDigits[(1/3)*Gamma[1/3]^2/Gamma[2/3], 10, 105]
  • PARI
    (1/3)*gamma(1/3)^2/gamma(2/3) \\ Michel Marcus, Aug 07 2017

Formula

Equals (1/3)*Beta(1/3,1/3).
Equals (1/3)*Gamma(1/3)^2/Gamma(2/3).
Equals A197374/3. - Michel Marcus, Jun 08 2020
From Peter Bala, Mar 01 2022: (Start)
Equals 2*Sum_{n >= 0} (1/(3*n+1) + 1/(3*n-2))*binomial(1/3,n). Cf. A002580 and A175576.
Equals Sum_{n >= 0} (-1)^n*(1/(3*n+1) - 1/(3*n-2))*binomial(1/3,n).
Equals hypergeom([1/3, 2/3], [4/3], 1) = (3/2)*hypergeom([-1/3, -2/3], [4/3], 1) = 2*hypergeom([1/3, 2/3], [4/3], -1) = hypergeom([-1/3, -2/3, 5/6], [4/3, -1/6], -1). (End)

A203126 Decimal expansion of (1/6)! = Gamma(7/6).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Dec 29 2011

Keywords

Examples

			.92771933363003920070834948253462101856646651914547557693612...
		

Crossrefs

Programs

Formula

Equals A175379/6. - R. J. Mathar, Jan 15 2021
A073006 * this * A231863 * A329219 = A202623. - R. J. Mathar, Jan 15 2021
Equals Integral_{x=0..oo} exp(-x^6) dx. - Ilya Gutkovskiy, Sep 18 2021

A204068 Decimal expansion of the Fresnel Integral Integral_{x>=0} sin(x^3) dx.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jan 10 2013

Keywords

Comments

Imaginary part associated with A204067.

Examples

			0.446489755784624605609282...
		

Crossrefs

Programs

  • Maple
    evalf(Pi/GAMMA(2/3)/3^(3/2) ) ;
  • Mathematica
    RealDigits[Gamma[1/3]/6, 10, 120][[1]] (* Amiram Eldar, May 26 2023 *)

Formula

Equals Pi/(Gamma(2/3)* 3^(3/2)) = A073010 / A073006.
(this value)^2 + A204067^2 = A202623^2.
Equals Gamma(1/3)/6 = A073005 / 6. - Amiram Eldar, May 26 2023

A205885 Decimal expansion of the Fresnel Integral int_{x=0..infinity} x*cos(x^3) dx.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Jan 10 2013

Keywords

Examples

			0.2256863232377334028242146713590856309...
		

Programs

  • Magma
    C := ComplexField(); [Gamma(2/3)/6]; // G. C. Greubel, Dec 13 2017
  • Maple
    evalf(GAMMA(2/3)/6) ;
  • Mathematica
    RealDigits[Gamma[2/3]/6, 10, 100][[1]] (* G. C. Greubel, Dec 13 2017 *)
  • PARI
    gamma(2/3)/6 \\ G. C. Greubel, Dec 13 2017
    

Formula

Equals A073006/6.

A059553 Beatty sequence for Gamma(2/3).

Original entry on oeis.org

1, 2, 4, 5, 6, 8, 9, 10, 12, 13, 14, 16, 17, 18, 20, 21, 23, 24, 25, 27, 28, 29, 31, 32, 33, 35, 36, 37, 39, 40, 41, 43, 44, 46, 47, 48, 50, 51, 52, 54, 55, 56, 58, 59, 60, 62, 63, 64, 66, 67, 69, 70, 71, 73, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 88, 89, 90, 92, 93, 94, 96
Offset: 1

Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059554.
Cf. A073006 (Gamma(2/3)).

Programs

  • Magma
    [Floor(n*Gamma(2/3)): n in [1..80]]; // Vincenzo Librandi, Jan 06 2015
  • Mathematica
    Floor[Range[100]*Gamma[2/3]] (* Paolo Xausa, Jul 05 2024 *)
  • PARI
    { default(realprecision, 100); b=gamma(2/3); for (n = 1, 2000, write("b059553.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009
    

Formula

a(n) = floor(n*Gamma(2/3)). - Michel Marcus, Jan 04 2015

A059554 Beatty sequence for Gamma(2/3)/(Gamma(2/3)-1).

Original entry on oeis.org

3, 7, 11, 15, 19, 22, 26, 30, 34, 38, 42, 45, 49, 53, 57, 61, 65, 68, 72, 76, 80, 84, 87, 91, 95, 99, 103, 107, 110, 114, 118, 122, 126, 130, 133, 137, 141, 145, 149, 152, 156, 160, 164, 168, 172, 175, 179, 183, 187, 191, 195, 198, 202, 206, 210, 214, 217, 221
Offset: 1

Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059553.
Cf. A073006.

Programs

  • Mathematica
    Floor[Range[100]*(1 + 1/(Gamma[2/3] - 1))] (* Paolo Xausa, Jul 05 2024 *)
  • PARI
    { default(realprecision, 100); b=gamma(2/3)/(gamma(2/3) - 1); for (n = 1, 2000, write("b059554.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009

Formula

a(n) = floor(n*gamma(2/3)/(gamma(2/3)-1)). - Michel Marcus, Jan 05 2015
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