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.

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A382713 Simple continued fraction expansion of sqrt(3/2).

Original entry on oeis.org

1, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2, 4, 2
Offset: 0

Views

Author

N. J. A. Sloane, Apr 08 2025

Keywords

Crossrefs

Essentially the same as A106469, A040003, A010694.

Programs

  • Maple
    with(numtheory); cfrac (sqrt(3/2, 70, 'quotients');
  • Mathematica
    PadRight[{1}, 100, {2, 4}] (* Paolo Xausa, Apr 14 2025 *)
  • Python
    def A382713(n): return 1<<1+(n&1) if n else 1 # Chai Wah Wu, Apr 09 2025

A379919 Numbers k that are the maximum of integers |k2|, |k3|, |k5| with |k2| + |k3| + |k5| > 0, and |k2*sqrt(2) + k3*sqrt(3) + k5*sqrt(5)| is smaller than for any smaller value of k.

Original entry on oeis.org

1, 2, 4, 5, 10, 27, 94, 151, 245, 296, 349, 396, 435, 1835, 10235, 18708, 31637, 53519, 160958, 535529, 643427
Offset: 1

Views

Author

Hugo Pfoertner, Jan 07 2025

Keywords

Comments

Maximum absolute value of coefficients in a linear combination of square roots of the first 3 primes producing a new best approximation of 0.
a(22) > 10^6.

Examples

			Signs of k2, k3, k5 chosen to get sum > 0.
   n  a(n)  *sqrt(2) *sqrt(3) *sqrt(5)        sum
   1     1        -1        1        0   3.1783724520E-1
   2     2         2        1       -2   8.8341977315E-2
   3     4        -4        2        1   4.3315343145E-2
   4     5        -3       -4        5   9.4959701042E-3
   5    10        10       -3       -4   1.7112910252E-3
   6    27       -22       27       -7   1.9758965307E-4
   7    94        94        2      -61   2.9850721518E-5
   8   151      -151      122        1   1.8582565467E-5
   9   245       245     -120      -62   1.1268156051E-5
  10   296      -190     -227      296   1.1170914545E-5
  11   349        39      349     -295   7.4116509219E-6
  12   396      -396      242       63   7.3144094166E-6
  13   435       435      107     -358   9.7241505322E-8
  14  1835      -932    -1608     1835   9.6348194355E-9
		

Crossrefs

Cf. A142238.
Previous Showing 11-12 of 12 results.