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.

A074962 Decimal expansion of Glaisher-Kinkelin constant A.

Original entry on oeis.org

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

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Author

Benoit Cloitre, Oct 05 2002

Keywords

Comments

Arises in expressions such as A002109(n) = 1^1*2^2*3^3*...*n^n which is asymptotic to A*n^(n^2/2 + n/2 + 1/12)*exp(-n^2/4). See A002109 for more references and links.
Named after the English mathematician and astronomer James Whitbread Lee Glaisher (1848-1928) and the Swiss mathematician Hermann Kinkelin (1832-1913). - Amiram Eldar, Jun 15 2021

Examples

			1.2824271291006226368753425688697917277676889273250011920637400217404...
		

References

  • Steven R. Finch, Mathematical constants, Encyclopedia of Mathematics and its Applications, Vol. 94, Cambridge University Press, 2003, p. 135.
  • Konrad Knopp, Theory and applications of infinite series, Dover, p. 555.

Crossrefs

Programs

  • Maple
    evalf(limit(product(k^k,k=1..n)/(n^(n^2/2+n/2+1/12)*exp(-n^2/4)),n=infinity),120); # Vaclav Kotesovec, Oct 23 2014
  • Mathematica
    RealDigits[Glaisher, 10, 111][[1]] (* Robert G. Wilson v *)
  • PARI
    x=10^(-100); exp(1/12-(zeta(-1+x)-zeta(-1))/x)
    
  • PARI
    exp(1/12-zeta'(-1)) \\ Charles R Greathouse IV, Dec 12 2013

Formula

A = 2^(1/36)*Pi^(1/6)*exp(1/3*(-Gamma/4 + s(2)/3 - s(3)/4 + ...)) where s(k) denotes Sum_{n>=0} 1/(2n+1)^k.
Closed expressions for A are exp(-zeta'(2)/2/Pi^2 + log(2*Pi)/12 + Gamma/12) or exp(1/12-zeta'(-1)).
Equals (2*Pi)^(1/4) / limit_{n->oo} Product_{k=1..n} Gamma(k/n)^(k/n^2). - Vaclav Kotesovec, Dec 02 2023
Equals (2*Pi*exp(gamma) * Product_{p prime} p^(1/(p^4-1)))^c, where gamma is Euler's constant (A001620), and c = Bernoulli(2)/2 = 1/12 (Van Gorder, 2012). - Amiram Eldar, Feb 08 2024
Equals e^(-1/4 + Integral_{x=1..2} x*log(sqrt(2*Pi)) - B_2(x) + x^2*Psi(x)/2 dx), where B_2(x) is the second Bernoulli polynomial and Psi(x) is the digamma function. - Andrea Pinos, Apr 16 2024
Equals exp(1/12 - 2*Integral_{x=0..oo} x*log(x)/(exp(2*Pi*x) - 1) dx) = exp(1/3 + 7*log(2)/36 - log(Pi)/6 + (2/3)*Integral_{x=0..1/2} log(Gamma(x+1)) dx) (see Finch). - Stefano Spezia, Dec 01 2024
From Antonio Graciá Llorente, May 03 2025: (Start)
Equals lim_{n->oo} (2^(13/3)*n)^(1/12) * Product_{k=1..n} (1 - 1/(2*k+1)^2)^((2*k+1)/6).
Equals lim_{n->oo} (24*n^2)^(1/24) * Product_{prime p<=n} (p^(1 - p/(p^2-1)) / sqrt(p^2-1))^(1/12). (End)

Extensions

More terms from Sascha Kurz, Feb 03 2003