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A242968 Decimal expansion of an Ising constant related to the triangular lattice. 2
8, 7, 9, 5, 8, 5, 3, 8, 6, 1, 6, 1, 5, 7, 1, 5, 1, 7, 0, 9, 3, 8, 9, 6, 0, 2, 8, 3, 0, 7, 9, 7, 2, 8, 4, 3, 0, 5, 6, 4, 8, 2, 0, 2, 9, 6, 7, 5, 9, 0, 7, 8, 0, 4, 4, 5, 3, 8, 3, 7, 5, 9, 7, 2, 3, 9, 8, 6, 1, 0, 1, 9, 6, 9, 8, 3, 6, 9, 7, 2, 1, 2, 9, 3, 9, 9, 6, 7, 4, 7, 5, 1, 8, 2, 0, 4, 8, 0, 1, 7, 5, 7, 7 (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. 399.

LINKS

Table of n, a(n) for n=0..102.

FORMULA

log(2) + log(3)/4 + H/2, where H is defined in A242967.

EXAMPLE

0.879585386161571517093896028307972843...

MATHEMATICA

H = Sqrt[3]/(6*Pi)*PolyGamma[1, 1/6]  -  Pi/Sqrt[3] - Log[6]; Log[2] + Log[3]/4 + H/2 // RealDigits[#, 10, 103] & // First

CROSSREFS

Cf. A242967, A242969.

Sequence in context: A276762 A256609 A269892 * A021536 A199389 A256490

Adjacent sequences:  A242965 A242966 A242967 * A242969 A242970 A242971

KEYWORD

nonn,cons

AUTHOR

Jean-Fran├žois Alcover, May 28 2014

STATUS

approved

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Last modified March 23 14:17 EDT 2019. Contains 321431 sequences. (Running on oeis4.)