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 1-2 of 2 results.

A010498 Decimal expansion of square root of 44.

Original entry on oeis.org

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

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Author

Keywords

Comments

Continued fraction expansion is 6 followed by {1, 1, 1, 2, 1, 1, 1, 12} repeated. [Harry J. Smith, Jun 05 2009]

Examples

			6.633249580710799698229865473341373367854177091178707194117364292232969...
		

Crossrefs

Cf. A040037 (continued fraction).

Programs

  • Mathematica
    RealDigits[N[Sqrt[44],200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Feb 24 2011 *)
  • PARI
    { default(realprecision, 20080); x=sqrt(44); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010498.txt", n, " ", d)); } \\ Harry J. Smith, Jun 05 2009

Formula

Equals 2*A010468. - R. J. Mathar, Jan 14 2021

A067280 Number of terms in continued fraction for sqrt(n), excl. 2nd and higher periods.

Original entry on oeis.org

1, 2, 3, 1, 2, 3, 5, 3, 1, 2, 3, 3, 6, 5, 3, 1, 2, 3, 7, 3, 7, 7, 5, 3, 1, 2, 3, 5, 6, 3, 9, 5, 5, 5, 3, 1, 2, 3, 3, 3, 4, 3, 11, 9, 7, 13, 5, 3, 1, 2, 3, 7, 6, 7, 5, 3, 7, 8, 7, 5, 12, 5, 3, 1, 2, 3, 11, 3, 9, 7, 9, 3, 8, 6, 5, 13, 7, 5, 5, 3, 1, 2, 3, 3, 6, 11, 3, 7, 6, 3, 9, 9, 11, 17, 5, 5, 12, 5
Offset: 1

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Author

Frank Ellermann, Feb 23 2002

Keywords

Examples

			a(2)=2: [1,(2)+ ]; a(3)=3: [1,(1,2)+ ]; a(4)=1: [2]; a(5)=2: [2,(4)+ ].
		

References

  • H. Davenport, The Higher Arithmetic. Cambridge Univ. Press, 7th edition, 1999, table 1.

Crossrefs

Related sequences: 2 : A040000, ..., 44: A040037, 48: A040041, ..., 51: A040043, 56: A040048, 60: A040052, 63: A040055, ..., 66: A040057. 68: A040059, 72: A040063, 80: A040071.
Related sequences: 45: A010135, ..., 47: A010137, 52: A010138, ..., 55: A010141, 57: A010142, ..., 59: A010144. 61: A010145, 62: A010146. 67: A010147, 69: A010148, ..., 71: A010150.
Cf. A003285.

Programs

  • Python
    from sympy import continued_fraction_periodic
    def A067280(n): return len((a := continued_fraction_periodic(0,1,n))[:1]+(a[1] if a[1:] else [])) # Chai Wah Wu, Jun 14 2022

Formula

a(n) = A003285(n) + 1. - Andrey Zabolotskiy, Jun 23 2020

Extensions

Name clarified by Michel Marcus, Jun 22 2020
Showing 1-2 of 2 results.