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.

A134915 a(0) = 1, a(n) = floor(a(n - 1)*Pi).

Original entry on oeis.org

1, 3, 9, 28, 87, 273, 857, 2692, 8457, 26568, 83465, 262213, 823766, 2587937, 8130243, 25541911, 80242279, 252088554, 791959549, 2488014301, 7816327450, 24555716894, 77144059797, 242355211526, 761381352089, 2391950062303, 7514532743484, 23607600862089, 74165465437218
Offset: 0

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Author

Rolf Pleisch, Jan 29 2008

Keywords

Comments

Coincides with first 11 terms of A085839.

Crossrefs

Essentially the same as A115239.

Programs

  • Mathematica
    NestList[Floor[# \[Pi]]&, 1, 30]  (* Harvey P. Dale, Mar 28 2011 *)

Formula

a(n) = A115239(n), n > 0. [From R. J. Mathar, Oct 27 2008]

A115239 a(1) = floor(Pi) = 3; a(n+1) = floor(a(n)*Pi).

Original entry on oeis.org

3, 9, 28, 87, 273, 857, 2692, 8457, 26568, 83465, 262213, 823766, 2587937, 8130243, 25541911, 80242279, 252088554, 791959549, 2488014301, 7816327450, 24555716894, 77144059797, 242355211526, 761381352089, 2391950062303
Offset: 1

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Author

Hieronymus Fischer, Jan 17 2006

Keywords

Comments

a(n+1)/a(n) converges to Pi. Similar to sequence A085839 but with a simpler definition.
Subset of the Beatty sequence of Pi = A022844 = floor(n*Pi). Primes in this sequence include a(1) = 3, a(6) = 857, a(15) = 25541911. - Jonathan Vos Post, Jan 18 2006

Examples

			a(2) = floor(a(1)*Pi) = floor(3*Pi) = 9;
a(3) = floor(a(2)*Pi) = floor(9*Pi) = 28;
a(4) = floor(a(3)*Pi) = floor(28*Pi) = 87.
		

Crossrefs

Programs

  • Maple
    A[1]:= 3:
    for n from 2 to 50 do A[n]:= floor(Pi*A[n-1]) od:
    seq(A[i],i=1..50); # Robert Israel, Feb 07 2016
  • Mathematica
    a[1] = Floor[Pi]; a[n_] := a[n] = Floor[a[n - 1]*Pi]; Array[a, 25] (* Robert G. Wilson v, Jan 18 2006 *)
    NestList[Floor[Pi #]&,3,30] (* Harvey P. Dale, Mar 30 2012 *)

Extensions

More terms from Robert G. Wilson v, Jan 18 2006

A085421 a(0)=2, a(1)=1, a(n+2)=floor[(e-1/e)*a(n+1)+a(n-2)].

Original entry on oeis.org

2, 1, 4, 10, 27, 73, 198, 538, 1462, 3974, 10802, 29363, 79816, 216962, 589764, 1603144, 4357797, 11845720, 32200005, 87528688, 237927642, 646754385, 1758060692, 4778904432, 12990409077, 35311592938, 95986861417
Offset: 0

Views

Author

Gary W. Adamson, Jun 29 2003

Keywords

Comments

a(n+1)/a(n) converges to e.
For n>0, floor[log a(n)] = n-1.
This resembles a Lucas sequence.

Crossrefs

Extensions

Edited by Don Reble, Nov 14 2005
Showing 1-3 of 3 results.