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 1-3 of 3 results.

A010502 Decimal expansion of square root of 48.

Original entry on oeis.org

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

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Author

Keywords

Comments

sqrt(48)/10 is the area enclosed by Koch's fractal snowflake based on unit-sided equilateral triangle (actually 8/5 times the latter's area). - Lekraj Beedassy, Jan 06 2005
7+sqrt(48) is the ratio of outer to inner Soddy circles' radii for three identical kissing circles (see Soddy circles link). - Lekraj Beedassy, Feb 14 2006
Continued fraction expansion is 6 followed by {1, 12} repeated. - Harry J. Smith, Jun 06 2009
Let a, b, c the sides of a triangle ABC of area S, then 4*sqrt(3) <= (a^2+b^2+c^2) / S; equality is obtained only when the triangle is equilateral (see Mitrinovic reference). - Bernard Schott, Sep 27 2022
Surface area of a gyroelongated square bipyramid (Johnson solid J_17) with unit edges. - Paolo Xausa, Aug 02 2025

Examples

			6.928203230275509174109785366023489467771221015241522512223227917807732...
		

References

  • J. N. Kapur, Mathematics Enjoyment For The Millions, Problem 47 pp. 64-67, Arya Book Depot, New Delhi 2000.
  • D. S. Mitrinovic, E. S. Barnes, D. C. B. Marsh, J. R. M. Radok, Elementary Inequalities, Tutorial Text 1 (1964), P. Noordhoff LTD, Groningen, problem 6.3, page 112.

Crossrefs

Cf. A040041 (continued fraction).
Cf. A002194, A104956, A010527, A152623 (other geometric inequalities).

Programs

  • Mathematica
    RealDigits[N[Sqrt[48],200]][[1]] (* Vladimir Joseph Stephan Orlovsky, Feb 24 2011 *)
  • PARI
    default(realprecision, 20080); x=sqrt(48); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b010502.txt", n, " ", d));  \\ Harry J. Smith, Jun 06 2009

Formula

Equals 4*A002194. - R. J. Mathar, Jul 31 2010
Equals A176053/A246724 - 7 (2nd comment and Soddy link). - Bernard Schott, Mar 17 2022
Equals 1/A020805. - Bernard Schott, Sep 28 2022

A249386 Decimal expansion of the constant 'a' appearing in the asymptotic expression of the number of plane partitions of n as a*n^(-25/36)*exp(b*n^(2/3)).

Original entry on oeis.org

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

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Author

Jean-François Alcover, Oct 27 2014

Keywords

Comments

The paper by Finch contains an error: the denominator should be sqrt(3*Pi), not sqrt(Pi). The constant 0.4009988836 is wrong. The formula in A000219 and the article by L. Mutafchiev and E. Kamenov (page 6) is correct. - Vaclav Kotesovec, Oct 27 2014. [In new version of prt.pdf is already corrected. - Vaclav Kotesovec, May 11 2015]

Examples

			0.231516813448898370560356406406332110855129212593287926597944524...
		

Crossrefs

Programs

  • Mathematica
    a = Zeta[3]^(7/36)*Exp[Zeta'[-1]]/(2^(11/36)*Sqrt[3*Pi]); RealDigits[a, 10, 104] // First

Formula

Equals zeta(3)^(7/36)*exp(zeta'(-1))/(2^(11/36)*sqrt(3*Pi)).
Equals exp(1/12) * A002117^(7/36) / (A074962 * 2^(11/36) * sqrt(3*Pi)). - Vaclav Kotesovec, Mar 02 2015

A321120 Decimal expansion of (3 + sqrt(3))/12.

Original entry on oeis.org

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

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Comments

The smallest weight in Holladay-Sard's quadrature formula for semi-infinite integrals.

Examples

			0.3943375672974064411272871951...
		

References

  • Harold J. Ahlberg, Edwin N. Nilson and Joseph L. Walsh, The Theory of Splines and Their Applications, Academic Press, 1967.

Crossrefs

Programs

  • Maple
    Digits := 1000; evalf((3 + sqrt(3))/12);
  • Mathematica
    RealDigits[(3 + Sqrt[3])/12, 10, 100][[1]]
  • PARI
    (3 + sqrt(3))/12

Formula

Equals lim_{n->infinity} A321118(0,n)/A321119(n).
Irrational number represented by the periodic continued fraction [0, 2, 1, 1; [6, 2]].
Largest real root of 1 - 12*x + 24*x^2.
Showing 1-3 of 3 results.