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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A073241 Decimal expansion of (1/Pi)^(1/Pi)^(1/Pi).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Jul 27 2002

Keywords

Examples

			0.45150834553657280522199381804...
		

Crossrefs

Cf. A000796 (Pi), A049541 (1/Pi), A073240 ((1/Pi)^(1/Pi)), A073243 (limit of (1/Pi)^(1/Pi)^...^(1/Pi)), A073242 (((1/Pi)^(1/Pi))^(1/Pi)), A073234 (Pi^Pi^Pi).

Programs

  • Mathematica
    With[{c=1/Pi},RealDigits[c^c^c,10,120][[1]]] (* Harvey P. Dale, Mar 10 2015 *)
  • PARI
    (1/Pi)^(1/Pi)^(1/Pi)

A165922 Decimal expansion of 2*sqrt(3)/(9*Pi).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Sep 30 2009

Keywords

Comments

The ratio of the volume of a regular tetrahedron to the volume of the circumscribed sphere. (The MathWorld link shows that the circumradius for a tetrahedron with side length a is a*sqrt(6)/4.)

Examples

			0.122517532315953788780294777402882098...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(2Sqrt[3])/(9Pi),10,120][[1]] (* Harvey P. Dale, Nov 17 2013 *)
  • PARI
    2*3^(-3/2)/Pi

Formula

2*sqrt(3)/(9*Pi) = A010469/(9*A000796) = (2/9)*A002194/A000796 = (2/9)*A002194*A049541 = 2*A020784/A000796 = 2*3^(-3/2)/Pi.

A092744 Decimal expansion of 1/Pi^4.

Original entry on oeis.org

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

Views

Author

Mohammad K. Azarian, Apr 12 2004

Keywords

Examples

			0.010265982254684335...
		

Crossrefs

Programs

A138345 a(n) = -1 if (n+1)-st decimal digit of 1/Pi is smaller than n-th digit of 1/Pi, 0 if they are equal, 1 if larger.

Original entry on oeis.org

-1, 1, -1, -1, 1, -1, 0, -1, -1, 1, -1, 1, 1, -1, 1, 1, -1, 1, -1, 1, 0, -1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, -1, -1, 1, -1, 1, 1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, 1, -1, -1, 1, -1, -1, 0, 1, 1, 1, 0, -1, 0, 1, 0, 1, -1, 1, 1, -1, -1, 1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, 1, 0, 1, -1, -1, 1, 0, -1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1
Offset: 1

Views

Author

Artur Jasinski, Mar 16 2008

Keywords

Crossrefs

Programs

  • Mathematica
    b = RealDigits[N[1/Pi, 1000]]; b = First[b]; a = {}; Do[k = b[[n + 1]] - b[[n]]; If[k < 0, AppendTo[a, -1], If[k == 0, AppendTo[a, 0], AppendTo[a, 1]]], {n, 1, 999}]; a (*Artur Jasinski*)
    Which[#[[2]]<#[[1]],-1,#[[2]]==#[[1]],0,True,1]&/@ Partition[ RealDigits[ 1/Pi,10,110][[1]],2,1] (* Harvey P. Dale, Aug 09 2013 *)

A165953 Decimal expansion of (5*sqrt(3) + sqrt(15))/(6*Pi).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Oct 02 2009

Keywords

Comments

The ratio of the volume of a regular dodecahedron to the volume of the circumscribed sphere (which has circumradius a*(sqrt(3) + sqrt(15))/4 = a*(A002194 + A010472)/4, where a is the dodecahedron's edge length; see MathWorld link). For similar ratios for other Platonic solids, see A165922, A049541, A165952, and A165954. A063723 shows the order of these by size.

Examples

			0.6649088942053266431144284467086337161648765805556919381057592605722964718...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(5*Sqrt[3]+Sqrt[15])/(6*Pi),10,120][[1]] (* Harvey P. Dale, Feb 16 2018 *)
  • PARI
    (5*sqrt(3)+sqrt(15))/(6*Pi)

Formula

Equals (5*A002194 + A010472)/(6*A000796).
Equals (5*A002194 + A010472)*A049541/6.
Equals (10*A010527 + A010472)*A049541/6.
Equals (5 + sqrt(5))/(2*Pi*sqrt(3)).
Equals (5 + A002163)*A049541*A020760/2.

A165954 Decimal expansion of sqrt(10 + 2*sqrt(5))/(2*Pi).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Oct 04 2009

Keywords

Comments

The ratio of the volume of a regular icosahedron to the volume of the circumscribed sphere (with circumradius a*sqrt(10 + 2*sqrt(5))/4 = a*A019881, where a is the icosahedron's edge length; see MathWorld link). For similar ratios for other Platonic solids, see A165922, A049541, A165952, and A165953. A063723 shows the order of these by size.

Examples

			0.6054613829125255833862652051280444903008454088014288933200935000838295683...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sqrt[10+2Sqrt[5]]/(2Pi),10,120][[1]] (* Harvey P. Dale, Aug 27 2013 *)
  • PARI
    sqrt(10+2*sqrt(5))/(2*Pi)

Formula

sqrt(10 + 2*sqrt(5))/(2*Pi) = sqrt(10 + 2*A002163)/(2*A000796) = 2*sin(2*Pi/5)/Pi = 2*sin(A019694)/A000796 = 2*sin(72 deg)/Pi = 2*A019881/A000796 = 2*A019881*A049541 = (2/Pi)*sin(72 deg) = A060294*A019881.

A293009 Decimal expansion of the first derivative of the infinite power tower function x^x^x... at x = 1/Pi.

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Mar 16 2018

Keywords

Examples

			0.56501844596024150528994096062245192028392680078511838285519...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Pi*Exp[-2*LambertW[Log[Pi]]]/(1+LambertW[Log[Pi]]), 10, 100][[1]] (* G. C. Greubel, Sep 09 2018 *)
  • PARI
    Pi*exp(-2*lambertw(log(Pi)))/(1+lambertw(log(Pi))) \\ Michel Marcus, Mar 16 2018

Formula

Equals Pi*exp(-2*LambertW(log(Pi)))/(1+LambertW(log(Pi))).

A073239 Decimal expansion of (1/Pi)^Pi.

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Jul 25 2002

Keywords

Comments

(1/Pi)^Pi = Pi^(-Pi) = 1/(Pi^Pi) (reciprocal of A073233).

Examples

			0.02742569312329810611955627085...
		

Crossrefs

Cf. A000796 (Pi), A049541 (1/Pi), A073238 (Pi^(1/Pi)), A073240 ((1/Pi)^(1/Pi)), A073233 (Pi^Pi).

Programs

  • Mathematica
    Join[{0},RealDigits[(1/Pi)^Pi,10,120][[1]]] (* Harvey P. Dale, Nov 30 2011 *)
  • PARI
    (1/Pi)^Pi

A092743 Decimal expansion of Pi^(-3).

Original entry on oeis.org

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

Views

Author

Mohammad K. Azarian, Apr 12 2004

Keywords

Examples

			0.0322515344331994...
		

Crossrefs

Programs

  • Mathematica
    Join[{0},RealDigits[Pi^-3,10,120][[1]]] (* Harvey P. Dale, Oct 10 2012 *)

A092746 Decimal expansion of Pi^(-6).

Original entry on oeis.org

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

Views

Author

Mohammad K. Azarian, Apr 12 2004

Keywords

Examples

			0.00104016147329585229...
		

Crossrefs

Programs

  • Maple
    evalf(1/Pi^6,100) ; # R. J. Mathar, May 12 2025
  • Mathematica
    Join[{0,0},RealDigits[Pi^-6,10,120][[1]]] (* Harvey P. Dale, Aug 16 2016 *)

Formula

Equals A092743^2 = 1/A092732. - R. J. Mathar, May 12 2025
Previous Showing 21-30 of 86 results. Next