login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A242967 Decimal expansion of H, an auxiliary constant used to evaluate some Ising-related constants on triangular and hexagonal lattices (negated). 6
1, 7, 6, 4, 2, 9, 7, 3, 3, 1, 3, 0, 8, 0, 2, 4, 3, 0, 3, 4, 4, 2, 9, 4, 8, 0, 4, 7, 6, 1, 6, 7, 0, 3, 0, 2, 3, 6, 1, 7, 8, 1, 4, 8, 8, 2, 8, 0, 0, 6, 9, 6, 2, 5, 2, 0, 1, 0, 3, 1, 9, 9, 1, 3, 2, 5, 8, 1, 2, 3, 5, 1, 1, 5, 1, 9, 5, 4, 4, 7, 2, 0, 6, 0, 5, 4, 1, 0, 3, 6, 3, 6, 3, 2, 9, 3, 8, 1, 5, 9, 6 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.22 Lenz-Ising constants, p. 400.

LINKS

Table of n, a(n) for n=0..100.

Eric Weisstein's MathWorld, Digamma Function

FORMULA

sqrt(3)/(6*Pi)*psi'(1/6) - Pi/sqrt(3) - log(6), where psi' is the derivative of the digamma function.

EXAMPLE

-0.1764297331308024303442948047616703...

MATHEMATICA

Sqrt[3]/(6*Pi)*PolyGamma[1, 1/6] - Pi/Sqrt[3] - Log[6] // RealDigits[#, 10, 101]& // First

CROSSREFS

Sequence in context: A131184 A021933 A154730 * A228628 A131266 A258094

Adjacent sequences:  A242964 A242965 A242966 * A242968 A242969 A242970

KEYWORD

nonn,cons

AUTHOR

Jean-François Alcover, May 28 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 October 21 18:43 EDT 2019. Contains 328308 sequences. (Running on oeis4.)