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 1-7 of 7 results.

A323983 Decimal expansion of sinh(Pi/6).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Feb 11 2019

Keywords

Comments

Decimal expansion of sum sigma_2 involved in calculation of i^i. [Uhler]

Examples

			0.5478534738880398084757156477174314033527835217758617619908956382877300771661...
		

Crossrefs

Programs

  • Mathematica
    a[0] = a[1] = 1; a[n_] := ((n - 2)^2 + 1) a[n - 2]; t[x_] := N[(1/2)^x*a[x]/x!, 128]; RealDigits[Sum[t[x], {x, 1, 421, 2}], 10, 111][[1]] (* Robert G. Wilson v, Feb 16 2019 *)
    RealDigits[Sinh[Pi/6], 10, 120][[1]] (* Vaclav Kotesovec, Feb 16 2019 *)

Formula

Extensions

More digits from Robert G. Wilson v, Feb 16 2019
Simpler definition from Vaclav Kotesovec, Feb 16 2019

A323984 Decimal expansion of exp(Pi/6).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Feb 11 2019

Keywords

Examples

			1.6880917949644686006168476280967822941196811892871823125684056078889433931696...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Exp[Pi/6], 10, 111][[1]] (* or *)
    a[0] = a[1] = 1; a[n_] := ((n - 2)^2 + 1) a[n - 2]; t[x_] := N[(1/2)^x*a[x]/x!, 128]; RealDigits[Sum[t[x], {x, 0, 421}], 10, 111][[1]] (* Robert G. Wilson v, Feb 16 2019 *)

Formula

Extensions

Corrected and extended by Robert G. Wilson v, Feb 16 2019

A323985 Decimal expansion of exp(-Pi/6).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Feb 11 2019

Keywords

Examples

			0.5923848471883889836654163326619194874141141457354587885866143313134832388373...
		

Crossrefs

Programs

Extensions

Corrected and extended by Robert G. Wilson v, Feb 16 2019

A323986 Decimal expansion of exp(Pi/3).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Feb 11 2019

Keywords

Examples

			2.8496539082263614974741273198529043939640061027811268817432387784881424491588...
		

Crossrefs

Programs

Extensions

Corrected and extended by Robert G. Wilson v, Feb 16 2019

A323987 Decimal expansion of exp(-Pi/3).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Feb 11 2019

Keywords

Examples

			0.3509198071784109675657367159969530583625731536209617406523848978345471913879...
		

Crossrefs

Programs

Extensions

Corrected and extended by Robert G. Wilson v, Feb 16 2019

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

A330865 Decimal expansion of cosh(Pi/2)/Pi.

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Apr 28 2020

Keywords

Examples

			(1 - 1/2^2) * (1 + 1/3^2) * (1 - 1/4^2) * (1 + 1/5^2) * (1 - 1/6^2) * ... = (e^(Pi/2) + e^(-Pi/2))/(2*Pi) = 0.7986963159564630848638067...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Cosh[Pi/2]/Pi, 10, 110] [[1]]
  • PARI
    cosh(Pi/2)/Pi \\ Michel Marcus, Apr 28 2020

Formula

Equals Sum_{k>=0} Pi^(2*k-1)/(4^k*(2*k)!).
Equals Product_{k>=2} (1 - (-1)^k/k^2).
Equals (i^(-i) + i^i)/(2*Pi), where i is the imaginary unit.
Showing 1-7 of 7 results.