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.

A242761 Decimal expansion of the escape probability for a random walk on the 3-D cubic lattice (a Polya random walk constant).

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, May 22 2014

Keywords

Examples

			0.6594626704490008571737268155670971...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.9, p. 322.

Crossrefs

Programs

  • Magma
    SetDefaultRealField(RealField(100)); R:= RealField(); (16*Sqrt(2/3)*Pi(R)^3)/(Gamma(1/24)*Gamma(5/24)*Gamma(7/24)*Gamma(11/24)); // G. C. Greubel, Oct 26 2018
  • Mathematica
    p = (16*Sqrt[2/3]*Pi^3)/(Gamma[1/24]*Gamma[5/24]*Gamma[7/24]*Gamma[11/24]); RealDigits[p, 10, 100] // First
  • PARI
    default(realprecision, 100); (16*sqrt(2/3)*Pi^3)/(gamma(1/24)* gamma(5/24)*gamma(7/24)*gamma(11/24)) \\ G. C. Greubel, Oct 26 2018
    

Formula

Equals (16*sqrt(2/3)*Pi^3)/(Gamma(1/24)*Gamma(5/24)*Gamma(7/24)*Gamma(11/24)), where Gamma is the Euler Gamma function.

A245067 Number of three-dimensional random walks with 2n steps in the wedge region x >= y >= z, beginning and ending at the origin without crossing the wedge boundary.

Original entry on oeis.org

1, 2, 12, 120, 1610, 25956, 474012, 9475752, 202921290, 4587734580, 108376022040, 2654745191280, 67043341981980, 1737717447946200, 46062204663294000, 1245096242017227360, 34239776369652506970, 956050033694583839220
Offset: 0

Views

Author

Jean-François Alcover, Nov 12 2014

Keywords

Examples

			For 2n=4, the 12 acceptable walks are:
(0, 0, -1), (0, -1, -1), (0, 0, -1), (0 ,0, 0);
(0, 0, -1), (0, 0, 0), (0, 0, -1), (0 ,0, 0);
(0, 0, -1), (0, 0, 0), (1, 0, 0), (0 ,0, 0);
(0, 0, -1), (1, 0, -1), (0, 0, -1), (0 ,0, 0);
(0, 0, -1), (1, 0, -1), (1, 0, 0), (0 ,0, 0);
(1, 0, 0), (0, -1, -1), (0, 0, -1), (0 ,0, 0);
(1, 0, 0), (0, 0, 0), (0, 0, -1), (0 ,0, 0);
(1, 0, 0), (0, 0, 0), (1, 0, 0), (0 ,0, 0);
(1, 0, 0), (1, 0, -1), (0, 0, -1), (0 ,0, 0);
(1, 0, 0), (1, 0, -1), (1, 0, 0), (0 ,0, 0);
(1, 0, 0), (1, 1, 0), (0, 0, -1), (0 ,0, 0);
(1, 0, 0), (1, 1, 0), (1, 0, 0), (0 ,0, 0).
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.9 Polya's random walk constants, p. 326.

Crossrefs

Programs

  • Mathematica
    a[n_] := CatalanNumber[n]*HypergeometricPFQ[{1/2, -n-1, -n}, {2, 2}, 4]; Table[a[n], {n, 0, 20}]

Formula

a(n) = sum_{k=0..n} (2n)!*(2k)!/((n-k)!*(n+1-k)!*k!^2*(k+1)!^2).
a(n) = C(n) * 3F2(1/2, -n-1, -n; 2, 2; 4) where C(n) is the n-th Catalan number and 3F2 the hypergeometric function.
a(n) ~ 2^(2*n-4) * 3^(2*n+9/2) / (Pi^(3/2) * n^(9/2)). - Vaclav Kotesovec, Nov 13 2014
Recurrence: n*(n+2)^2*a(n) = 2*(2*n-1)*(10*n^2 + 2*n - 3)*a(n-1) - 36*(n-1)*(2*n-3)*(2*n-1)*a(n-2). - Vaclav Kotesovec, May 14 2016

A241624 Decimal expansion of 'c', one of Polya's Random Walk constants, related to the asymptotics of the number of 3-D random walks starting from and returning to the origin.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, May 19 2014

Keywords

Examples

			0.53923817508158141965602919129297773...
		

References

  • Steven R. Finch, Mathematical Constants, Cambridge, 2003, Section 5.9 p. 325.

Crossrefs

Programs

  • Mathematica
    m3 = A086231 = Sqrt[6]/32/Pi^3*Gamma[1/24]*Gamma[5/24]*Gamma[7/24]*Gamma[11/24]; c = 9/32*(m3 + 6/(Pi^2*m3)); RealDigits[c, 10, 100] // First

Formula

c = 9/32*(m3 + 6/(Pi^2*m3)), where m3 = A086231.
Previous Showing 11-13 of 13 results.