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 1-8 of 8 results.

A175314 Decimal expansion of exp(Pi) + exp(-Pi).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Apr 01 2010

Keywords

Examples

			23.1839065510430412555035041051202753...
		

Crossrefs

Cf. A039661 (exp(Pi)), A093580 (exp(-Pi)), A175315, A334402 (cosh(Pi)).

Programs

Formula

Equals A039661 + A093580.
Equals 2*cosh(Pi).
Equals 10 * Product_{k>=1} (1 + 4/(2*k+1)^2). - Amiram Eldar, Aug 09 2020

A175315 Decimal expansion of exp(Pi) - exp(-Pi).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Apr 01 2010

Keywords

Examples

			23.0974787145154967559546686307...
		

Crossrefs

Cf. A039661 (exp(Pi)), A093580 (exp(-Pi)), A175314.

Programs

Formula

Equals A039661 - A093580.
Equals 2*sinh(Pi).

A334401 Decimal expansion of sinh(Pi).

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Apr 26 2020

Keywords

Comments

This constant is transcendental.

Examples

			(e^Pi - e^(-Pi))/2 = 11.5487393572577483779773343153884...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sinh[Pi], 10, 110] [[1]]

Formula

Equals Sum_{k>=0} Pi^(2*k+1)/(2*k+1)!.
Equals 2 * Product_{k>=1} (4*k^2+4)/(4*k^2-1).

A334402 Decimal expansion of cosh(Pi).

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Apr 26 2020

Keywords

Comments

This constant is transcendental.

Examples

			(e^Pi + e^(-Pi))/2 = 11.5919532755215206277517520525601...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Cosh[Pi], 10, 110] [[1]]

Formula

Equals Sum_{k>=0} Pi^(2*k)/(2*k)!.
Equals Product_{k>=0} (1 + 4/(2*k+1)^2).
Equals Product_{k>=1} (k^2 + 4)/(k^2 + 1). - Amiram Eldar, Aug 09 2020

A135544 Decimal expansion of (-1)^(I Pi).

Original entry on oeis.org

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

Views

Author

Marvin Ray Burns, Feb 22 2008, Feb 23 2008

Keywords

Examples

			(-1)^(I*Pi) = exp(-Pi)^(Pi) = 0.000051723186...
		

Crossrefs

Programs

  • Mathematica
    N[(-1)^(I Pi), 1000] FullSimplify[(-1)^(I Pi) == Exp[ -Pi]^Pi == (Exp[ -(1/2)*Pi])^(2*Pi) == Sqrt[Exp[ -Pi]^Pi/(Exp[Pi]^Pi)] == Exp[(-1/2*Pi)]^(Gamma[1/6]*Gamma[5/6]) == 1/(Sqrt[Exp[Pi]^(2*Pi)]) == (Exp[ -(1/2)*Pi])^(2*Pi) == Exp[ -Pi^2]]
    Join[{0, 0, 0, 0}, RealDigits[(Exp[-Pi])^(Pi), 10, 96][[1]]] (* G. C. Greubel, Oct 18 2016 *)
  • PARI
    exp(-Pi^2) \\ Charles R Greathouse IV, Jan 23 2025
    
  • PARI
    real((-1)^(I*Pi)) \\ Charles R Greathouse IV, Jan 23 2025

Formula

a(n) = (-1)^(I Pi) = exp(-Pi)^Pi = (exp( -(1/2)*Pi))^(2*Pi) = sqrt(exp( -Pi)^Pi/(exp(Pi)^Pi)) = exp[(-1/2*Pi)]^(Gamma[1/6]*Gamma[5/6]) = 1/(sqrt[exp[Pi]^(2*Pi)]) = (exp[ -(1/2)*Pi])^(2*Pi) = exp[ -Pi^2].

Extensions

Offset corrected R. J. Mathar, Jan 26 2009

A101748 Decimal expansion of an i^i, namely exp(3*Pi/2).

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Nov 19 2004

Keywords

Comments

This number multiplied by A101749 = A093580.
i^i = exp(-Pi/2 +- 2*k*Pi).

Examples

			This i^i = 111.31777...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[E^(3Pi/2), 10, 111][[1]]

Extensions

Edited by Don Reble, Nov 08 2005

A101749 Decimal expansion of one of the values of i^i, namely exp(-5*Pi/2).

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Nov 19 2004

Keywords

Comments

A101748 multiplied by this number = A093580.
i^i = exp(-Pi/2 +- 2*k*Pi).

Examples

			This i^i = 0.00038820320...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[E^(-5Pi/2), 10, 111][[1]]

Extensions

Edited by Don Reble, Nov 08 2005

A196535 Decimal expansion of Sum_{j=0..oo} exp(-Pi*(2*j+1)^2).

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Oct 03 2011

Keywords

Examples

			0.04321391826429779829201838202725...
		

References

  • Jolley, Summation of Series, Dover (1961) eq (114) on page 22.
  • A. P. Prudnikov, Yu. A. Brychkov, and O. I. Marichev, Integrals and Series, Vol. 1 (Overseas Publishers Association, Amsterdam, 1986), p. 729, formula 14.

Crossrefs

Programs

  • Maple
    (root[4](2)-1)*GAMMA(1/4)/2^(11/4)/Pi^(3/4) ; evalf(%) ;
  • Mathematica
    RealDigits[ EllipticTheta[2, 0, Exp[-4*Pi]]/2, 10, 105] // First // Prepend[#, 0]&  (* Jean-François Alcover, Feb 12 2013 *)

Formula

Equals (2^(1/4)-1) * Gamma(1/4) / ( 2^(11/4) * Pi^(3/4) ).
Equals theta2(exp(-4*Pi))/2.

Extensions

12 more digits from Jean-François Alcover, Feb 12 2013
Showing 1-8 of 8 results.