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.

A248270 Egyptian fraction representation of sqrt(44) (A010498) using a greedy function.

Original entry on oeis.org

6, 2, 8, 122, 18919, 402739144, 764123173937021975, 2148666191962903360885805290461855276, 8622580654686644746427953833014483269744901669599325824509666827330296874
Offset: 0

Views

Author

Robert G. Wilson v, Oct 04 2014

Keywords

Crossrefs

Cf. A010498.
Egyptian fraction representations of the square roots: A006487, A224231, A248235-A248322.
Egyptian fraction representations of the cube roots: A129702, A132480-A132574.

Programs

  • Mathematica
    Egyptian[nbr_] := Block[{lst = {IntegerPart[nbr]}, cons = N[ FractionalPart[ nbr], 2^20], denom, iter = 8}, While[ iter > 0, denom = Ceiling[ 1/cons]; AppendTo[ lst, denom]; cons -= 1/denom; iter--]; lst]; Egyptian[ Sqrt[ 44]]

A040037 Continued fraction for sqrt(44).

Original entry on oeis.org

6, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1
Offset: 0

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Keywords

Examples

			6.633249580710799698229865473... = 6 + 1/(1 + 1/(1 + 1/(1 + 1/(2 + ...)))). - _Harry J. Smith_, Jun 05 2009
		

References

  • James J. Tattersall, Elementary Number Theory in Nine Chapters, Cambridge University Press, 1999, page 276.

Crossrefs

Cf. A010498 (decimal expansion).

Programs

  • Maple
    Digits := 100: convert(evalf(sqrt(N)),confrac,90,'cvgts'):
  • Mathematica
    ContinuedFraction[Sqrt[44],300] (* Vladimir Joseph Stephan Orlovsky, Mar 06 2011 *)
    PadRight[{6},80,{12,1,1,1,2,1,1,1}] (* Harvey P. Dale, Apr 02 2013 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 14000); x=contfrac(sqrt(44)); for (n=0, 20000, write("b040037.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 05 2009

Formula

From Amiram Eldar, Nov 12 2023: (Start)
Multiplicative with a(2) = 1, a(4) = 2, a(2^e) = 12 for e >= 3, and a(p^e) = 1 for an odd prime p.
Dirichlet g.f.: zeta(s) * (1 + 5/2^(3*s-1) + 1/4^s). (End)
G.f.: (6 + x + x^2 + x^3 + 2*x^4 + x^5 + x^6 + x^7 + 6*x^8)/(1 - x^8). - Stefano Spezia, Jul 27 2025

A041074 Numerators of continued fraction convergents to sqrt(44).

Original entry on oeis.org

6, 7, 13, 20, 53, 73, 126, 199, 2514, 2713, 5227, 7940, 21107, 29047, 50154, 79201, 1000566, 1079767, 2080333, 3160100, 8400533, 11560633, 19961166, 31521799, 398222754, 429744553, 827967307, 1257711860
Offset: 0

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Author

Keywords

Crossrefs

Programs

Formula

G.f.: -(x^15 -6*x^14 +7*x^13 -13*x^12 +20*x^11 -53*x^10 +73*x^9 -126*x^8 -199*x^7 -126*x^6 -73*x^5 -53*x^4 -20*x^3 -13*x^2 -7*x -6) / ((x^8 -20*x^4 +1)*(x^8 +20*x^4 +1)). - Colin Barker, Nov 04 2013

A041075 Denominators of continued fraction convergents to sqrt(44).

Original entry on oeis.org

1, 1, 2, 3, 8, 11, 19, 30, 379, 409, 788, 1197, 3182, 4379, 7561, 11940, 150841, 162781, 313622, 476403, 1266428, 1742831, 3009259, 4752090, 60034339, 64786429, 124820768, 189607197, 504035162, 693642359, 1197677521, 1891319880, 23893516081, 25784835961
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Magma
    I:=[1, 1, 2, 3, 8, 11, 19, 30, 379, 409, 788, 1197, 3182, 4379, 7561, 11940]; [n le 16 select I[n] else 398*Self(n-8)-Self(n-16): n in [1..40]]; // Vincenzo Librandi, Dec 11 2013
  • Mathematica
    Table[Denominator[FromContinuedFraction[ContinuedFraction[Sqrt[44],n]]],{n,1,50}] (* Vladimir Joseph Stephan Orlovsky, Mar 22 2011 *)
    Denominator[Convergents[Sqrt[44], 30]] (* Vincenzo Librandi, Dec 11 2013 *)
    LinearRecurrence[{0,0,0,0,0,0,0,398,0,0,0,0,0,0,0,-1},{1,1,2,3,8,11,19,30,379,409,788,1197,3182,4379,7561,11940},40] (* Harvey P. Dale, Feb 12 2025 *)

Formula

G.f.: -(x^2-x-1)*(x^4+3*x^2+1)*(x^8+10*x^4+1) / ((x^8-20*x^4+1)*(x^8+20*x^4+1)). - Colin Barker, Nov 12 2013
a(n) = 398*a(n-8) - a(n-16). - Vincenzo Librandi, Dec 11 2013

Extensions

More terms from Colin Barker, Nov 12 2013
Showing 1-4 of 4 results.