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.

Previous Showing 11-16 of 16 results.

A039922 Continued fraction for root of x^5 - x - 1.

Original entry on oeis.org

1, 5, 1, 42, 1, 3, 24, 2, 2, 1, 16, 1, 11, 1, 1, 2, 31, 1, 12, 5, 1, 7, 11, 1, 4, 1, 4, 2, 2, 3, 4, 2, 1, 1, 11, 1, 41, 12, 1, 8, 1, 1, 1, 1, 1, 9, 2, 1, 5, 4, 1, 25, 4, 6, 11, 1, 4, 1, 6, 1, 1, 1, 2, 2, 2, 4, 11, 1, 4, 1, 3, 2, 8, 1, 3, 3, 6, 21, 11, 2, 1, 1, 10, 2, 1, 3
Offset: 0

Views

Author

Keywords

Examples

			1.16730397826141868425604589... = 1 + 1/(5 + 1/(1 + 1/(42 + 1/(1 + ...)))).
		

Crossrefs

Cf. A160155 Decimal expansion.

Programs

  • PARI
    { allocatemem(932245000); default(realprecision, 21000); x=NULL; p=x^5 - x - 1; rs=polroots(p); r=real(rs[1]); c=contfrac(r); for (n=1, 20001, write("b039922.txt", n-1, " ", c[n])); } \\ Harry J. Smith, May 03 2009
    
  • PARI
    contfrac(polrootsreal(x^5-x-1)[1]) \\ Charles R Greathouse IV, Apr 14 2014

A039923 Continued fraction for 2^(1/3) + sqrt(3).

Original entry on oeis.org

2, 1, 123, 1, 1, 3, 1, 1, 5, 7, 2, 3, 2, 4, 1, 18, 5, 1, 13, 3, 3, 3, 4, 1, 69, 2, 1, 1, 7, 1, 1, 3, 1, 1, 13, 2, 5, 2, 1, 3, 1, 2, 38, 3, 1, 2, 1, 1, 2, 1, 5, 1, 1, 1446, 1, 1, 6, 1, 2, 5, 1, 1, 9, 4, 1, 5, 2, 1, 4, 5, 1, 1, 18, 3, 3, 2, 24, 3, 1, 1, 1, 2, 74, 3, 2, 4, 3, 1
Offset: 0

Views

Author

Keywords

Comments

2^(1/3) + sqrt(3) = 2^(1/3) + 3^(1/2). - Harry J. Smith, May 09 2009

Examples

			2.9919718574637504582946569... = 2 + 1/(1 + 1/(123 + 1/(1 + 1/(1 + ...)))). - _Harry J. Smith_, May 09 2009
		

Crossrefs

Cf. A160331 = Decimal expansion. - Harry J. Smith, May 09 2009

Programs

  • PARI
    { allocatemem(932245000); default(realprecision, 21000); x=contfrac(2^(1/3)+3^(1/2)); for (n=1, 20001, write("b039923.txt", n-1, " ", x[n])); } \\ Harry J. Smith, May 09 2009

A181495 Positions of the incrementally largest terms in continued fraction for 2^(1/3).

Original entry on oeis.org

1, 2, 4, 10, 12, 32, 36, 572, 1991, 20857, 27432, 28763, 155122, 190271, 288108, 484709, 1395499, 9370521, 12918396, 22646948, 49496125, 73469408, 172128260, 645676547
Offset: 1

Views

Author

John M. Campbell, Oct 23 2010

Keywords

Comments

The corresponding records (or high-water marks) in A002945, the continued fraction for 2^(1/3), are {1, 3, 5, 8, 14, 15, 534, 7451, 12737, 22466, 68346, 148017, 217441, 320408, 533679, 4156269, 4886972, 10253793, ...} - see A268515.
It is not known if this sequence is infinite (i.e., whether the continued fraction expansion is bounded). [Davenport]. - N. J. A. Sloane, Feb 07 2016

References

  • H. Davenport, The Higher Arithmetic: An Introduction to the Theory of Numbers, Cambridge, 2008.

Crossrefs

Programs

  • Mathematica
    Use Max[ContinuedFraction[2^(1/3), n]] for some positive integer n, e.g. Max[ContinuedFraction[2^(1/3), 288108]].
    cf = ContinuedFraction[2^(1/3), 20000000]; mx = 0; k = 1; lst = {}; While[k < 20000000, If[ cf[[k]] > mx, mx = cf[[k]]; AppendTo[lst, k]; Print[{k, cf[[k]]}]]; k++ ]; lst (* Robert G. Wilson v, Oct 24 2010 *)

Extensions

a(19) from Robert G. Wilson v, Oct 24 2010
a(20)-a(21) from Zak Seidov, Feb 08 2016
a(22)-a(24) from Hans Havermann, Feb 08 2016

A110483 Continued fraction for seventh root of 2.

Original entry on oeis.org

1, 9, 1, 1, 1, 1, 5, 46, 1, 3, 2, 1, 1, 3, 1, 1, 2, 1, 22, 48, 1, 1, 5, 4, 1, 1, 1, 1, 1, 1, 2, 8, 1, 6, 1, 21, 1, 1, 1, 1, 1, 6, 1, 1, 3, 3, 1, 1, 2, 2, 2, 3, 1, 26, 1, 16, 1, 4, 21, 1, 2, 1, 1, 1, 5, 3, 7, 21, 3, 1, 1, 1, 8, 1, 8, 1, 4, 1, 24, 1, 3, 1, 6, 1, 2, 1, 5, 5, 6, 1, 12, 1, 8, 2, 2, 1, 3, 1, 1, 2
Offset: 0

Views

Author

Paul Stoeber (pstoeber(AT)uni-potsdam.de), Sep 09 2005

Keywords

Crossrefs

Programs

  • Haskell
    import Ratio
    floorRoot :: Integer -> Integer -> Integer
    floorRoot k n | k>=1 && n>=1 = h n where h x = let y=((k-1)*x+n`div`x^(k-1))`div`k in if y (Integer,Rational)
    intFrac x = let ((a,b),~(q,r)) = ((numerator x,denominator x),divMod a b) in (q,r%b)
    cf :: Rational -> Rational -> [Integer]
    cf x y = let ((xi,xf),(yi,yf)) = (intFrac x,intFrac y) in if xi==yi then xi : cf (recip xf) (recip yf) else []
    y = 2^512 -- increase to get more terms, decrease to get a quick answer
    (k,n) = (7,2) -- compute continued fraction for k-th root of n
    main = print (let x = floorRoot k (n*y^k) in cf (x%y) ((x+1)%y))
  • Mathematica
    ContinuedFraction[Surd[2,7],100] (* Harvey P. Dale, Aug 11 2017 *)

A159824 Continued fraction for Pi^Pi (cf. A073233).

Original entry on oeis.org

36, 2, 6, 9, 2, 1, 2, 5, 1, 1, 6, 2, 1, 291, 1, 38, 50, 1, 2, 5, 4, 1, 2, 2, 1, 5, 1, 4, 13, 2, 1, 4, 3, 3, 1, 2, 25, 1, 1, 1, 2, 2, 1, 1, 1, 2, 2, 3, 1, 43, 1, 2, 7, 3, 1, 1, 1, 2, 4, 2, 1, 1, 3, 1, 3, 3, 2, 2, 16, 3, 5, 2, 1, 5, 2, 1, 10, 1, 1, 3, 1, 13, 1, 1, 3, 1, 10, 4, 1, 1, 1, 38, 1, 2, 2, 1, 1, 3
Offset: 0

Views

Author

Harry J. Smith, Apr 30 2009

Keywords

Examples

			36.4621596072079117709908260... = 36 + 1/(2 + 1/(6 + 1/(9 + 1/(2 + ...)))).
		

Crossrefs

Programs

  • Mathematica
    ContinuedFraction[Pi^Pi,200] (* Vladimir Joseph Stephan Orlovsky, Jul 20 2010 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 21000); x=contfrac(Pi^Pi); for (n=1, 20001, write("b159824.txt", n-1, " ", x[n])); }

Extensions

Edited by N. J. A. Sloane, Jul 22 2010

A076595 First occurrence of n as a term in the continued fraction for the cube root of 2.

Original entry on oeis.org

1, 15, 2, 7, 4, 64, 56, 10, 59, 14, 148, 18, 117, 12, 32, 638, 578, 112, 229, 371, 218, 91, 878, 2209, 139, 108, 182, 975, 484, 314, 859, 1977, 454, 597, 1016, 205, 1425, 136, 315, 4201, 51, 3661, 1009, 143, 2188, 3532, 381, 550, 151, 786, 2815, 1444, 654
Offset: 1

Views

Author

Benoit Cloitre, Oct 20 2002

Keywords

Crossrefs

Programs

  • Mathematica
    With[{cf=ContinuedFraction[Surd[2,3],4500]},Flatten[Table[Position[cf,n,{1},1],{n,60}]]] (* Harvey P. Dale, Jul 01 2015 *)
  • PARI
    default(realprecision, 1500); v=contfrac(2^(1/3)); a(n)=if(n<0,0,s=1; while(abs(n-component(v,s))>0,s++); s)
Previous Showing 11-16 of 16 results.