OFFSET
1,2
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 7.7 Riesz-Kolmogorov Constants, p. 474.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
FORMULA
Equals Product_{k>=1} (1 + 1/A002145(k)^2)/(1 - 1/A002145(k)^2) = A243381 / A243379. - Vaclav Kotesovec, Apr 30 2020
EXAMPLE
1.3468852519994065951820075554411...
MAPLE
s:= convert(evalf(Pi^2/(8*Catalan), 140), string):
map(parse, subs("."=NULL, [seq(i, i=s)]))[]; # Alois P. Heinz, May 23 2014
MATHEMATICA
RealDigits[Pi^2/(8*Catalan), 10, 100] // First
PROG
(PARI) default(realprecision, 100); Pi^2/(8*Catalan) \\ G. C. Greubel, Aug 25 2018
(Magma) SetDefaultRealField(RealField(100)); R:=RealField(); Pi(R)^2/(8*Catalan(R)); // G. C. Greubel, Aug 25 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, May 23 2014
STATUS
approved