A242968 Decimal expansion of an Ising constant related to the triangular lattice.

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

Offset: 0

Author

Jean-François Alcover, May 28 2014

Keywords

• nonn
• cons

Examples

			0.879585386161571517093896028307972843...
		

References

• Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.22 Lenz-Ising constants, p. 399.

Crossrefs

Cf. A242967, A242969.

Programs

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

Formula

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