A242967 Decimal expansion of H, an auxiliary constant used to evaluate some Ising-related constants on triangular and hexagonal lattices (negated).

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

Offset: 0

Author

Jean-François Alcover, May 28 2014

Keywords

• nonn
• cons

Examples

			-0.1764297331308024303442948047616703...
		

References

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

Links

• Eric Weisstein's MathWorld, Digamma Function

Programs

Mathematica

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

Formula

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