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 1-4 of 4 results.

A069655 Maximum element in the simple continued fraction expansion for (1+1/n)^n.

Original entry on oeis.org

2, 4, 3, 3, 20, 16, 11, 34, 18, 128, 56, 168, 39, 21, 162, 116, 37, 113, 72, 105, 73, 245, 244, 74, 159, 187, 253, 663, 101, 166, 34, 41, 87, 71, 46, 449, 181, 1874, 130, 215, 457, 317, 196, 256, 160, 107, 72, 147, 209, 114, 2632, 134, 252, 844, 1285, 341, 656
Offset: 1

Views

Author

Benoit Cloitre, May 09 2002

Keywords

Comments

Limit_{n -> infinity} (1+1/n)^n = e.

Examples

			The simple continued fraction expansion of (1+1/10)^10 is [2, 1, 1, 2, 5, 1, 128, 1, 2, 12, 5, 3, 46, 1, 11, 7], hence a(10) = 128.
		

Crossrefs

Programs

  • Mathematica
    Table[ Max[ ContinuedFraction[ (1 + 1/n)^n]], {n, 1, 60}]

A071529 Number of 1's among the elements of the simple continued fraction for (1+1/n)^n.

Original entry on oeis.org

0, 0, 1, 1, 1, 4, 7, 7, 12, 5, 8, 10, 23, 18, 25, 14, 18, 17, 14, 24, 22, 22, 35, 15, 21, 30, 29, 33, 37, 30, 27, 47, 49, 44, 54, 55, 53, 51, 46, 46, 43, 60, 64, 65, 79, 64, 64, 67, 73, 66, 79, 68, 60, 76, 86, 85, 85, 83, 86, 74, 90, 84, 93, 106, 90, 85, 98, 107, 88, 104, 86
Offset: 1

Views

Author

Benoit Cloitre, Jun 02 2002

Keywords

Comments

It seems that lim_{n->infinity} a(n)/A069887(n) = C = 0.41..., which is close to (log(4)-log(3))/log(2)=0.415..., the expected density of 1's (cf. measure theory of continued fractions).

Examples

			(1+1/14)^14 has for continued fraction [2, 1, 1, 1, 2, 6, 1, 7, 1, 6, 2, 1, 4, 21, 1, 1, 7, 1, 1, 1, 3, 2, 7, 2, 7, 1, 2, 4, 1, 3, 2, 1, 1, 1, 5, 1, 2, 5, 1, 2] which contains 18 "1's" hence a(14)=18.
		

Programs

  • Mathematica
    Table[Count[ContinuedFraction[(1+1/n)^n],1],{n,80}] (* Harvey P. Dale, Mar 11 2013 *)
  • PARI
    for(n=1,100,s=(1+1/n)^n; print1(sum(i=1,length(contfrac(s)),if(1-component(contfrac(s),i),0,1)),","))

A070154 Number of terms in the simple continued fraction expansion of Sum_{k=0..n}(-1)^k/(2k+1), the Leibniz-Gregory series for Pi/4.

Original entry on oeis.org

1, 3, 4, 9, 5, 9, 14, 10, 10, 19, 16, 21, 22, 22, 24, 20, 19, 24, 28, 28, 29, 30, 39, 31, 44, 40, 44, 33, 41, 47, 44, 48, 54, 48, 60, 49, 63, 51, 65, 72, 64, 70, 78, 64, 79, 77, 74, 87, 75, 86, 82, 94, 88, 106, 106, 94, 104, 108, 87, 107, 86, 106, 98, 110, 115, 110, 105, 115
Offset: 0

Views

Author

Benoit Cloitre, May 06 2002

Keywords

Comments

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

Examples

			The simple continued fraction for Sum(k=0,10,(-1)^k/(2k+1)) is [0, 1, 4, 4, 1, 3, 54, 1, 2, 1, 1, 4, 11, 1, 2, 2] which contains 16 elements, hence a(10)=16.
		

Crossrefs

Programs

  • Mathematica
    lcf[f_] := Length[ContinuedFraction[f]]; lcf /@ Accumulate[Table[(-1)^k/(2*k + 1), {k, 0, 100}]] (* Amiram Eldar, Apr 29 2022 *)
  • PARI
    for(n=1,100,print1( length(contfrac(sum(i=0,n,(-1)^i/(2*i+1)))),","))

Formula

Limit_{n -> infinity} a(n)/n = C = 1.6...

Extensions

Offset changed to 0 and a(0) inserted by Amiram Eldar, Apr 29 2022

A071599 Product of elements in the simple continued fraction for (1+1/n)^n.

Original entry on oeis.org

2, 8, 24, 216, 4320, 19008, 103488, 1292544, 1548288, 3264307200, 24710676480, 54623600640, 16562257920, 3345695539200, 8216950210560, 33673108783104000, 205682009702400000, 15655109317676236800, 12302792042521559040000
Offset: 1

Views

Author

Benoit Cloitre, Jun 01 2002

Keywords

Comments

It appears that lim_{n->oo} a(n)^(1/A069887(n)) = A002210 (Khinchin constant = 2.68...). - Benoit Cloitre, Jan 29 2006

Examples

			The continued fraction for (1+1/5)^5 is [2, 2, 20, 1, 9, 2, 3] and 2*2*20*1*9*2*3=4320 hence a(5)=4320
		

Programs

  • Mathematica
    Table[Times@@ContinuedFraction[(1+1/n)^n],{n,20}] (* Harvey P. Dale, May 02 2019 *)
  • PARI
    a(n) = prod(i=1, length(contfrac((1+1/n)^n)), component(contfrac((1+1/n)^n), i));
Showing 1-4 of 4 results.