cp's OEIS Frontend

A222391 Decimal expansion of e^2/sqrt(Pi).

%I A222391 #21 Jan 10 2017 08:06:01
%S A222391 4,1,6,8,8,2,8,4,8,3,2,6,6,6,9,2,2,3,0,4,2,1,3,0,3,9,0,7,7,5,2,3,1,0,
%T A222391 2,6,0,3,8,6,6,6,4,6,8,1,1,4,8,4,9,9,6,3,7,8,3,0,0,0,8,9,5,4,6,2,4,0,
%U A222391 4,3,2,2,7,2,0,1,5,3,6,0,9,2,7,9,8,1,9
%N A222391 Decimal expansion of e^2/sqrt(Pi).
%H A222391 G. C. Greubel, <a href="/A222391/b222391.txt">Table of n, a(n) for n = 1..5000</a>
%F A222391 Equals A072334*A087197.
%F A222391 Equals decimal expansion of Sum_{n >= 1} 1/(Gamma(n/2)*Gamma((n+1)/2)).
%e A222391 4.1688284832666922304213039077523102603866646811484996378300089546240432...
%p A222391 Digits:=100: evalf(exp(1)^2/sqrt(Pi)); # _Wesley Ivan Hurt_, Jan 09 2017
%t A222391 RealDigits[E^2/Sqrt[Pi], 10, 90][[1]]
%o A222391 (PARI) (exp(1))^2/sqrt(Pi) \\ _G. C. Greubel_, Jan 09 2017
%Y A222391 Cf. A072334, A087197, A222392.
%Y A222391 Cf. A096789: Sum_{n >= 1} 1/(Gamma(n)*Gamma(n+1)).
%Y A222391 Cf. A035009 (see fourth comment).
%K A222391 nonn,cons
%O A222391 1,1
%A A222391 _Bruno Berselli_, Mar 19 2013