OFFSET
-1,1
FORMULA
Equals Sum_{i>=1} 1/(i*(i+1)*(i+2)^2).
For n>1, a(n) = A072691(n+1).
EXAMPLE
0.072467033424113218236207583323...
MATHEMATICA
RealDigits[(Pi^2 - 9)/12, 10, 100][[1]] (* Amiram Eldar, May 17 2022 *)
PROG
(PARI) (Pi^2-9)/12 \\ Charles R Greathouse IV, Oct 01 2022
CROSSREFS
KEYWORD
AUTHOR
Zak Seidov, Mar 12 2007
STATUS
approved