A274400 Decimal expansion of 'V', the value of a 4-dimensional iterated integral studied by David Broadhurst in connection with Quantum Field Theory (negated).

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

Offset: 0

Author

Jean-François Alcover, Jun 20 2016

Keywords

• nonn
• cons

Examples

			-0.0390127263601671660175669413545004617574758571386130990149389673954...
		

References

• Jonathan Borwein and Peter Borwein, Experimental and Computational Mathematics: Selected Writings, Perfectly Scientific Press, 2010, p. 106.

Links

• D. J. Broadhurst, Massive 3-loop Feynman diagrams reducible to SC* primitives of algebras of the sixth root of unity, arXiv:hep-th/9803091, 1998;

Crossrefs

Cf. A255685 ('U' in Borwein & Borwein).

Programs

Mathematica

digits = 101;
v[k_] := ((-1)^k*((24*(k - 1)*(3*k - 4))/(3*k - 2)^3 + (8*(3*k*(3*k - 5) + 4))/(27*(k - 1)^3) + PolyGamma[2, (3*k)/2 - 1] - PolyGamma[2, (3*(k - 1))/2]))/(48*(k - 1)*(3*k - 4)*(3*k - 2));
V = 3 Zeta[3]/8 - 1/2 + NSum[v[k], {k, 2, Infinity}, WorkingPrecision -> digits + 10, Method -> "AlternatingSigns"]; Join[{0},
RealDigits[V, 10, digits][[1]]]

Formula

V = Sum_{j>k>0} (-1)^j cos(2Pi k/3)/(j^3 k).

Equals 3 zeta(3)/8-1/2+Sum_{k>=2} ((-1)^k*((24*(k - 1)*(3*k - 4))/(3*k - 2)^3 + (8*(3*k*(3*k - 5) + 4))/(27*(k - 1)^3) + PolyGamma(2, (3*k)/2 - 1) - PolyGamma(2, (3*(k - 1))/2)))/(48*(k - 1)*(3*k - 4)*(3*k - 2)).