login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A245592 Decimal expansion of the Ising constant K_c, the ratio of the coupling constant to the ferromagnetic critical temperature, in the two-dimensional case. 2
4, 4, 0, 6, 8, 6, 7, 9, 3, 5, 0, 9, 7, 7, 1, 5, 1, 2, 6, 1, 6, 3, 0, 4, 6, 6, 2, 4, 8, 9, 8, 9, 6, 1, 5, 4, 5, 1, 4, 0, 8, 0, 1, 6, 4, 1, 3, 0, 8, 1, 7, 7, 0, 5, 3, 7, 6, 6, 4, 7, 8, 0, 4, 3, 2, 6, 6, 8, 8, 5, 9, 2, 1, 1, 1, 0, 1, 3, 0, 4, 3, 9, 1, 6, 8, 5, 3, 4, 4, 5, 9, 5, 5, 1, 2, 8, 0, 2, 1, 4, 2, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.22 Lenz-Ising Constants, p. 396.

LINKS

Table of n, a(n) for n=0..101.

Andrei Okounkov, Limit shapes, real and imagined, Bull. Amer. Math. Soc. 53 2 (2016), 187-216

Wikipedia, Ising Model

FORMULA

K_c = (1/2)*log(1 + sqrt(2)) = (1/2)*A091648.

Equals Integral_{0..1} x/sqrt(1 + x^4) dx. - Peter Bala, Oct 28 2019

Equals arcsinh(1)/2. - Peter Luschny, Oct 29 2019

EXAMPLE

0.4406867935097715126163046624898961545140801641308177053766478...

MATHEMATICA

RealDigits[(1/2)*Log[1 + Sqrt[2]], 10, 102] // First

CROSSREFS

Cf. A091648.

Sequence in context: A155502 A228048 A016705 * A169783 A133657 A121455

Adjacent sequences:  A245589 A245590 A245591 * A245593 A245594 A245595

KEYWORD

nonn,cons,easy

AUTHOR

Jean-Fran├žois Alcover, Jul 30 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 1 09:53 EDT 2020. Contains 334762 sequences. (Running on oeis4.)