A242969 Decimal expansion of an Ising constant related to the hexagonal lattice.

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

Offset: 1

Author

Jean-François Alcover, May 28 2014

Keywords

• nonn
• cons

Examples

			1.0250590964713132201744730083644777...
		

References

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

Crossrefs

Cf. A242967, A242968.

Programs

Mathematica

H = Sqrt[3]/(6*Pi)*PolyGamma[1, 1/6] - Pi/Sqrt[3] - Log[6]; 3/4*Log[2] + Log[3]/2 + H/4 // RealDigits[#, 10, 100]& // First

Formula

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