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 1-3 of 3 results.

A057156 Number of functions from {0,1}^n to {0,1}^n.

Original entry on oeis.org

1, 4, 256, 16777216, 18446744073709551616, 1461501637330902918203684832716283019655932542976, 39402006196394479212279040100143613805079739270465446667948293404245721771497210611414266254884915640806627990306816
Offset: 0

Views

Author

Henry Bottomley, Aug 15 2000

Keywords

Comments

a(n) is the number of subdivisions of the Brownian motion on the unit interval at the n-th stage of subdivision. - Stephen Crowley, Apr 12 2007

Examples

			a(1)=4 since the possibilities are f(0)=0, f(1)=0; f(0)=0, f(1)=1; f(0)=1, f(1)=0; f(0)=1, f(1)=1.
For n=3: we need to count maps from a set with 8 points to a set with 8 points.  There are 8^8 such functions, that is, a(3) = 8^8 = 2^24 = 16777216. - _N. J. A. Sloane_, Mar 05 2023
		

References

  • François Robert, Discrete Iterations: A Metric Study, Springer-Verlag, 1986, p. 167.
  • Norbert Wiener, Nonlinear Problems in Random Theory, MIT Press Classic, 1958, Lecture 1.

Crossrefs

Programs

  • Mathematica
    lst={};Do[AppendTo[lst,(2^n)^(2^n)],{n,0,8}];lst (* Vladimir Joseph Stephan Orlovsky, Mar 02 2009 *)
  • PARI
    a(n)=1<<(n<Charles R Greathouse IV, Jan 19 2012

Formula

a(n) = (2^n)^(2^n) = A000312(A000079(n)) = A000079(A036289(n)) = A001146(n)^n = A000722(n) + A057157(n).
Sum_{n>=1} 1/a(n) = A134880. - Amiram Eldar, Nov 15 2020

Extensions

More terms from Vladimir Joseph Stephan Orlovsky, Mar 02 2009

A134883 Decimal expansion of Sum_{n>=1} 1/(n^n+1).

Original entry on oeis.org

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

Views

Author

Artur Jasinski, Nov 15 2007

Keywords

Comments

Constant formed from sum of reversed Sierpinski numbers of first kind A014566.

Examples

			0.7399479434954655122560255307349947820561106657422439628745456519998...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[Sum[1/(n^n + 1), {n, 1, 150}], 100]][[1]] (* first zero removed *)

A134882 Decimal expansion of Sum_{x>=1} 1/(Pi^x)^(Pi^x).

Original entry on oeis.org

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

Views

Author

Artur Jasinski, Nov 14 2007

Keywords

Examples

			0.02742569327699137828116119484312083268225595388057...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[Sum[1/(Pi^n)^(Pi^n), {n, 1, 20}], 200]][[1]] (* first two zeros removed *)
Showing 1-3 of 3 results.