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A274440
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Decimal expansion of Q(2), value of one of five integrals related to Quantum Field Theory (see the paper by David Broadhurst).
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4
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2, 2, 6, 0, 3, 9, 9, 2, 4, 8, 1, 2, 0, 4, 6, 3, 6, 8, 9, 9, 6, 0, 9, 2, 9, 0, 6, 6, 2, 4, 0, 8, 9, 5, 0, 3, 1, 9, 3, 0, 7, 6, 1, 5, 0, 0, 1, 6, 3, 3, 2, 1, 3, 8, 8, 8, 9, 4, 8, 8, 9, 0, 4, 2, 3, 2, 9, 0, 8, 5, 7, 4, 8, 5, 6, 8, 7, 2, 5, 7, 0, 5, 8, 8, 7, 5, 0, 4, 7, 0, 4, 6, 7, 8, 6, 2, 0, 3, 7, 4, 5, 0, 7, 5
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OFFSET
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1,1
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LINKS
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FORMULA
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Q(n) = Integral_{x>0} arccosh((x+2)/2)^2 log((x+1)/x)/(x+n) dx.
Computation is done using the analytical form given by David Broadhurst:
Q(2) = -Cl2(Pi/3)^2 + 53/16 zeta(4) + 5/2 U, where Cl_2 is the Clausen integral and U is A255685.
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EXAMPLE
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2.260399248120463689960929066240895031930761500163321388894889042329...
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MATHEMATICA
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Cl2[x_] := (I/2)*(PolyLog[2, Exp[-I*x]] - PolyLog[2, Exp[I*x]]);
U = A255685 = Pi^4/180 + (Pi^2/12)*Log[2]^2 - (1/12)*Log[2]^4 - 2*PolyLog[4, 1/2];
Q[2] = -Cl2[Pi/3]^2 + 53/16 Zeta[4] + 5/2 U;
RealDigits[N[Q[2], 104] // Chop][[1]]
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PROG
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(PARI)
Q(n) = intnum(x=0, oo, acosh((x+2)/2)^2 * log((x+1)/x)/(x+n));
(PARI)
clausen(n, x) = my(z = polylog(n, exp(I*x))); if (n%2, real(z), imag(z));
u31=Pi^4/180 + (Pi^2/12)*log(2)^2 - (1/12)*log(2)^4 - 2*polylog(4, 1/2);
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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