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%I #7 Oct 31 2018 09:09:19
%S 4,3,0,6,2,0,7,6,0,0,7,3,0,8,0,8,6,5,2,9,1,9,8,3,7,1,5,9,8,4,2,2,0,9,
%T 4,4,9,2,4,1,1,8,5,2,3,5,4,1,2,9,3,4,1,1,4,2,2,4,9,4,9,1,1,7,8,1,9,9,
%U 0,4,3,4,3,3,0,8,2,3,8,3,3,5,1,5,6,7,0,4,8,6,6,5,7,1,7,3,0,9,7,4
%N Decimal expansion of the volume of the Löbell polyhedron L(5).
%H Taiyo Inoue, <a href="https://arxiv.org/abs/0809.2111">Organizing Volumes of Right-Angled Hyperbolic Polyhedra</a>, arXiv:0809.2111 [math.GT], 2008.
%e 4.3062076007308086529198371598422094492411852354129341142249491178199...
%t theta[n_] := Pi/2 - ArcCos[1/(2 Cos[Pi/n])];
%t lambda[z_] := -Integrate[Log[Abs[2 Sin[t]]], {t, 0, z}];
%t vol[n_] := n/2 (2 lambda[theta[n]] + lambda[theta[n] + Pi/n] + lambda[theta[n] - Pi/n] - lambda[2 theta[n] - Pi/2]);
%t RealDigits[N[vol[5], 100] // Chop] // First
%Y Cf. A144222.
%K nonn,cons
%O 1,1
%A _Jean-François Alcover_, Oct 30 2018
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