%I #11 May 06 2024 09:23:51

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

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

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

%N Decimal expansion of Pi^(1/2)*Gamma(1/18)/(9*Gamma(5/9)).

%C Constant from generalized Pi integrals: the case of n=18.

%H Takayuki Tatekawa, <a href="/A372327/b372327.txt">Table of n, a(n) for n = 1..10001</a>

%F Equals 2*Integral_{x=0..1} dx/sqrt(1-x^18).

%F Equals Gamma(1/18)^2 / (9 * 2^(8/9) * Gamma(1/9)). - _Vaclav Kotesovec_, Apr 29 2024

%e 2.14999545849204723391222945664...

%t RealDigits[Sqrt[Pi]/9*Gamma[1/18]/Gamma[5/9], 10, 5001][[1]]

%Y Cf. A085565, A113477, A262427, A371929, A371930.

%K nonn,cons,new

%O 1,1

%A _Takayuki Tatekawa_, Apr 28 2024