(MAGMAMagma) C<i> := ComplexField(); [Sqrt(2*Pi(C)*Exp(1))/21]; // G. C. Greubel, Nov 17 2017
OEIS Server: https://oeis.org/edit/global/2944
proposed
approved
editing
0.1967967311486901399271138992523739356878819960472...
(PARI) sqrt(2*Pi*exp(1))/21 \\ G. C. Greubel, Nov 17 2017
(MAGMA) C<i> := ComplexField(); [Sqrt(2*Pi(C)*Exp(1))/21]; // G. C. Greubel, Nov 17 2017
_N. J. A. Sloane_._
RealDigits[Sqrt[2Pi E]/21, 10, 120][[1]] (* Harvey P. Dale, Oct 26 2014 *)