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 31-40 of 55 results. Next

A059551 Beatty sequence for Gamma(1/3).

Original entry on oeis.org

2, 5, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 34, 37, 40, 42, 45, 48, 50, 53, 56, 58, 61, 64, 66, 69, 72, 75, 77, 80, 83, 85, 88, 91, 93, 96, 99, 101, 104, 107, 109, 112, 115, 117, 120, 123, 125, 128, 131, 133, 136, 139, 141, 144, 147, 150, 152, 155, 158, 160, 163
Offset: 1

Views

Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059552.
Cf. A073005 (Gamma(1/3)).

Programs

  • Magma
    [Floor(n*Gamma(1/3)): n in [1..80]]; // Vincenzo Librandi, Jan 07 2015
  • Mathematica
    Table[Floor[n Gamma[1/3]], {n, 70}] (* Vincenzo Librandi, Jan 07 2015 *)
  • PARI
    { default(realprecision, 100); b=gamma(1/3); for (n = 1, 2000, write("b059551.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009
    

Formula

a(n) = floor(n*Gamma(1/3)). - Michel Marcus, Jan 04 2015

A059552 Beatty sequence for Gamma(1/3)/(Gamma(1/3)-1).

Original entry on oeis.org

1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 19, 20, 22, 23, 25, 27, 28, 30, 31, 33, 35, 36, 38, 39, 41, 43, 44, 46, 47, 49, 51, 52, 54, 55, 57, 59, 60, 62, 63, 65, 67, 68, 70, 71, 73, 74, 76, 78, 79, 81, 82, 84, 86, 87, 89, 90, 92, 94, 95, 97, 98, 100, 102, 103, 105, 106, 108
Offset: 1

Views

Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059551.
Cf. A073005.

Programs

  • Magma
    [Floor(n*Gamma(1/3)/(Gamma(1/3)-1)): n in [1..80]]; // Vincenzo Librandi, Jan 06 2015
  • Mathematica
    Floor[Range[100]*(1 + 1/(Gamma[1/3] - 1))] (* Paolo Xausa, Jul 05 2024 *)
  • PARI
    { default(realprecision, 100); b=gamma(1/3)/(gamma(1/3) - 1); for (n = 1, 2000, write("b059552.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009
    

Formula

a(n) = floor(n*Gamma(1/3)/(Gamma(1/3)-1)). - Michel Marcus, Jan 04 2015

A249206 Decimal expansion of the logarithmic capacity of the unit equilateral triangle.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Oct 23 2014

Keywords

Examples

			0.421753934648426824238122958592773059107710633283...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 4.9 Integer Chebyshev constants, p. 268.

Crossrefs

Programs

  • Mathematica
    k = (Sqrt[3]/(8*Pi^2))*Gamma[1/3]^3; RealDigits[k, 10, 102] // First

Formula

k = (sqrt(3)/(8*Pi^2))*Gamma(1/3)^3.

A271923 Numerator of (1/3)*(Product_{j=0..n-1} (((2*j+1)*(3*j+4))/((j+1)*(6*j+1))) - 1).

Original entry on oeis.org

1, 5, 29, 52, 913, 1693, 69769, 658529, 1667651, 57873, 1616141, 1035959, 79918969, 3244922897, 3402714857, 6606018008, 51386679347, 5504537914811, 622652618545649, 10572475711004, 10931562934889, 235301799307039, 4608689892802861, 9034390134407023, 488936376609325, 959905250448181
Offset: 1

Views

Author

N. J. A. Sloane, May 04 2016

Keywords

Examples

			1, 5/3, 29/13, 52/19, 913/285, 1693/465, 69769/17205, 658529/147963, 1667651/ 345247, 57873/11137, 1616141/291153, 1035959/175741, 79918969/12829093, ...
		

Crossrefs

Sequences of fractions from de Gier paper: A271919-A271926.
Cf. A271924 (denominators), A073005, A186706.

Programs

  • Maple
    f3:=proc(n) local j;
    (1/3)*(mul(((2*j+1)*(3*j+4))/((j+1)*(6*j+1)),j=0..n-1)-1); end;
    t3:=[seq(f3(n),n=1..50)];
    map(numer,t3);
    map(denom,t3);
  • Mathematica
    a[n_] := (1/3)*(Product[((2*j + 1)*(3*j + 4))/((j + 1)*(6*j + 1)), {j, 0, n - 1}] - 1) // Numerator;
    Array[a, 26] (* Jean-François Alcover, Nov 30 2017 *)

Formula

a(n)/A271924(n) ~ c * (2*n)^(2/3), where c = Gamma(1/3)*sqrt(3)/(2*Pi) = A073005/A186706. - Amiram Eldar, Aug 17 2025

A271925 Numerator of (Product_{j=0..n-1} (((2*j+1)*(3*j+4))/((j+1)*(6*j+1))) - 1).

Original entry on oeis.org

3, 5, 87, 156, 913, 1693, 69769, 658529, 5002953, 173619, 1616141, 3107877, 239756907, 3244922897, 3402714857, 6606018008, 51386679347, 5504537914811, 622652618545649, 10572475711004, 10931562934889, 235301799307039, 4608689892802861, 9034390134407023, 488936376609325, 959905250448181
Offset: 1

Views

Author

N. J. A. Sloane, May 04 2016

Keywords

Examples

			3, 5, 87/13, 156/19, 913/95, 1693/155, 69769/5735, 658529/49321, 5002953/345247, 173619/11137, 1616141/97051, 3107877/175741, 239756907/12829093, ...
		

Crossrefs

Sequences of fractions from de Gier paper: A271919-A271926.
Cf. A271926 (denominators), A073005, A186706.

Programs

  • Maple
    f3:=proc(n) local j;
    (mul(((2*j+1)*(3*j+4))/((j+1)*(6*j+1)),j=0..n-1)-1); end;
    t3:=[seq(f3(n),n=1..50)];
    map(numer,t3);
    map(denom,t3);
  • Mathematica
    Table[Product[(2*j+1)*(3*j+4)/((j+1)*(6*j+1)),{j,0,n-1}]-1, {n,1,20}]//Numerator (* Vaclav Kotesovec, Oct 13 2017 *)

Formula

a(n)/A271926(n) ~ c * (2*n)^(2/3), where c = Gamma(1/3)*3^(3/2)/(2*Pi) = 3*A073005/A186706. - Amiram Eldar, Aug 17 2025

A358559 Decimal expansion of Bi(0), where Bi is the Airy function of the second kind.

Original entry on oeis.org

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

Views

Author

Dumitru Damian, Nov 22 2022

Keywords

Examples

			0.61492662744600073515092236909361355359472818864859650504087875301429651...
		

References

  • F. W. J. Olver, Asymptotics and Special Functions, Academic Press, ISBN 978-0-12-525856-2, 1974.
  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 56, page 559.

Crossrefs

Cf. A284867 (Ai(0)), A284868 (Ai'(0)), this sequence (Bi(0)), A358561 (Bi'(0)), A358564(Gi(0)).

Programs

  • Mathematica
    RealDigits[AiryBi[0], 10, 120][[1]] (* Amiram Eldar, Nov 28 2022 *)
  • PARI
    airy(0)[2]
    
  • PARI
    airy(0)[1]*sqrt(3)
    
  • PARI
    3^(1/3)*gamma(1/3)/(2*Pi)
    
  • SageMath
    airy_bi(0).n(algorithm='scipy', prec=250)

Formula

Bi(0) = A284867*A002194.
Bi(0) = A358564*3.
Bi(0) = 1/(3^(1/6)*A073006).
Bi(0) = A073005/(3^(1/6)*A186706).
Bi(0) = A073005/(3^(1/6)*2*A093602).
Bi(0) = 3^(1/3)*A073005/(2*A000796).
Bi(0) = A252799/(3^(1/6)*BarnesG[5/3]).
Bi(0) = 3^(1/4)/(2^(2/9) * Pi^(1/3) * AGM(2,(sqrt(2+sqrt(3))))^(1/3)), where AGM is the arithmetic-geometric mean.

A358561 Decimal expansion of the derivative Bi'(0), where Bi is the Airy function of the second kind.

Original entry on oeis.org

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

Views

Author

Dumitru Damian, Nov 22 2022

Keywords

Examples

			0.44828835735382635791482371039882839086622679921226206108280877837233075...
		

References

  • F. W. J. Olver, Asymptotics and Special Functions, Academic Press, ISBN 978-0-12-525856-2, 1974.

Crossrefs

Cf. A284867 (Ai(0)), A284868 (Ai'(0)), A358559 (Bi(0)), this sequence (Bi'(0)), A358564 (Gi(0)).

Programs

  • Mathematica
    RealDigits[AiryBi'[0], 10, 120][[1]] (* Amiram Eldar, Nov 28 2022 *)
  • PARI
    derivnum(x=0, airy(x)[2])
    
  • SageMath
    airy_bi_prime(0).n(algorithm='scipy', prec=250)

Formula

Bi'(0) = A284868*A002194.
Bi'(0) = 3*Gi'(0), where Gi' is the derivative of the inhomogeneous Airy function of the first kind.
Bi'(0) = 3^(1/6)/A073005.
Bi'(0) = A073006*3^(1/6)/A186706.
Bi'(0) = A073006*3^(1/6)/2*A093602.
Bi'(0) = 3^(2/3)*A073006/(2*A000796).
Bi'(0) = 3^(1/4)*AGM(2,(sqrt(2+sqrt(3))))^(1/3)/(2^(7/9) * Pi^(2/3)), where AGM is the arithmetic-geometric mean.

A358564 Decimal expansion of Gi(0), where Gi is the inhomogeneous Airy function of the first kind (also called Scorer function).

Original entry on oeis.org

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

Views

Author

Dumitru Damian, Nov 22 2022

Keywords

Examples

			0.204975542482000245050307456364537851198242729549532168346959584338098839...
		

References

  • Scorer, R. S., Numerical evaluation of integrals of the form Integral_{x=x1..x2} f(x)*e^(i*phi(x))dx and the tabulation of the function Gi(z)=(1/Pi)*Integral_{u=0..oo} sin(u*z+u^3/3) du, Quart. J. Mech. Appl. Math. 3 (1950), 107-112.

Crossrefs

Cf. A284867 (Ai(0)), A284868 (Ai'(0)), A358559 (Bi(0)), A358561 (Bi'(0)), this sequence (Gi(0)).

Programs

  • Mathematica
    First[RealDigits[N[ScorerGi[0],90]]] (* Stefano Spezia, Nov 28 2022 *)
  • PARI
    airy(0)[2]/3
    
  • PARI
    1/(3^(7/6)*gamma(2/3))
    
  • PARI
    sqrt(3)*gamma(1/3)/(3^(7/6)*2*Pi)
    
  • PARI
    1/(3^(3/4)*2^(2/9)*Pi^(1/3)*sqrtn(agm(2,(sqrt(2+sqrt(3)))),3))
    
  • SageMath
    1/(3^(7/6)*gamma(2/3)).n(algorithm='scipy', prec=250)

Formula

Gi(0) = A358559/3.
Gi(0) = A284867/A002194.
Gi(0) = Hi(0)/2, where Hi is the inhomogeneous Airy function of the second kind.
Gi(0) = 1/(3^(7/6)*A073006).
Gi(0) = A073005/(3^(7/6)*A186706).
Gi(0) = A073005/(3^(7/6)*2*A093602).
Gi(0) = A073005/(3^(4/6)*2*A000796).
Gi(0) = A252799/(3^(7/6)*BarnesG(5/3)).
Gi(0) = 1/(3^(3/4) * 2^(2/9) * Pi^(1/3) * AGM(2,(sqrt(2+sqrt(3))))^(1/3)), where AGM is the arithmetic-geometric mean.

A371881 Decimal expansion of Gamma(1/20).

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Apr 15 2024

Keywords

Examples

			19.4700853112555128640473209677271275456304195833419756810827837553645...
		

Crossrefs

Programs

  • Maple
    evalf(GAMMA(1/20), 130);  # Alois P. Heinz, Apr 15 2024
  • Mathematica
    RealDigits[Gamma[1/20], 10, 120][[1]]
    RealDigits[2^(33/40) * 5^(5/16) * (1 + Sqrt[5])^(1/8) * Sqrt[5^(1/4) + Sqrt[2 + Sqrt[5]]] * Sqrt[Pi * Gamma[1/10]] * QPochhammer[E^(-2*Sqrt[5]*Pi)] / E^(Sqrt[5]*Pi/12), 10, 120][[1]]

Formula

Equals 2^(33/40) * 5^(5/16) * (1 + sqrt(5))^(1/8) * sqrt(5^(1/4) + sqrt(2 + sqrt(5))) * sqrt(Pi*Gamma(1/10)) * QPochhammer(exp(-2*sqrt(5)*Pi)) / exp(sqrt(5)*Pi/12).

A091546 First column of the array A092077 ((8,2)-Stirling2).

Original entry on oeis.org

1, 56, 10192, 3872960, 2517424000, 2497284608000, 3511182158848000, 6643156644540416000, 16275733779124019200000, 50129260039701979136000000, 189588861470152885092352000000, 863766852858016544480755712000000, 4666068539139005373285042356224000000, 29489553167358513959161467691335680000000
Offset: 1

Views

Author

Wolfdieter Lang, Feb 13 2004

Keywords

Comments

Also seventh column (m=6) of triangle A091543.

Crossrefs

Programs

  • Mathematica
    a[n_] := 6^(2*n) * Pochhammer[1/6, n] * Pochhammer[1/3, n] / 2; Array[a, 20] (* Amiram Eldar, Aug 30 2025 *)

Formula

a(n) = (2^(n-1))*Product_{j=0..n-1} ((3*j+1)*(6*j+1)), n>=1. From eq.12 of the Blasiak et al. reference with r=8, s=2, k=1.
a(n) = (6^(2*n))*risefac(1/6, n)*risefac(1/3, n)/2, n>=1, with risefac(x, n) = Pochhammer(x, n).
a(n) = fac6(6*n-5)*fac6(6*n-4)/2, n>=1, with fac6(6*n-5) = A008542(n) and fac6(6*n-4)/2 = A034689(n)= (2^(n-1))*A007559(n), (6-factorials).
a(n) ~ Pi * (6/e)^(2*n) * n^(2*n-1/2) / (Gamma(1/6) * Gamma(1/3)). - Amiram Eldar, Aug 30 2025
Previous Showing 31-40 of 55 results. Next