OFFSET
1,2
REFERENCES
S. R. Finch, Mathematical Constants, Cambridge, 2003, p. 232.
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..10000
S. R. Finch, Several Constants Arising in Statistical Mechanics, Ann. Comb. 3(2-4) (1999), 323-335.
Antonio Gracia Llorente, Infinite Product Formula Involving the Catalan's Constant, OSF Preprint, 2024.
FORMULA
Equals A097469^2. - Vaclav Kotesovec, Dec 30 2020
Equals Product_{k>=1} (((4*k-1)^3*(4*k+3))/((4*k+1)^3*(4*k-3)))^k. - Antonio GraciĆ” Llorente, Jul 22 2024
EXAMPLE
1.791622812069593424730547089...
MAPLE
evalf(exp(2*Catalan/Pi));
MATHEMATICA
RealDigits[Exp[(2*Catalan)/Pi], 10, 120][[1]] (* Harvey P. Dale, Jul 17 2011 *)
PROG
(PARI) exp(2*Catalan/Pi) \\ Charles R Greathouse IV, Jul 15 2014
(Magma) R:=RealField(100); Exp(2*Catalan(R)/Pi(R)); // G. C. Greubel, Aug 23 2018
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
R. J. Mathar, Jul 18 2007
STATUS
approved