A243311 - OEIS

%I #9 Dec 24 2024 10:43:45

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

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

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

%N Decimal expansion of the volume of a regular ideal hyperbolic 4-simplex.

%D Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.9 Hyperbolic volume constants, p. 512.

%F Equals 10*Pi/3*arcsin(1/3) - Pi^2/3.

%e 0.268895660169311225469294867227245664524994437...

%t RealDigits[10*Pi/3*ArcSin[1/3] - Pi^2/3, 10, 102] // First

%o (PARI) 10*Pi/3*asin(1/3) - Pi^2/3 \\ _Stefano Spezia_, Dec 24 2024

%Y Cf. A019503, A143298 (Gieseking's constant is also the volume of a regular ideal hyperbolic 3-simplex).

%K nonn,cons,easy

%O 0,1

%A _Jean-François Alcover_, Jun 03 2014