OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
FORMULA
Sqrt(Sum_{n>=1}((1/2)*n^3 + (1/2)*n + 1)/n!). - Alexander R. Povolotsky, Oct 01 2011
EXAMPLE
3.1421532925425807337006835045314966069705383584581530419234...
MAPLE
Digits:=100: evalf(sqrt(4*exp(1)-1)); # Wesley Ivan Hurt, Nov 24 2016
MATHEMATICA
RealDigits[Sqrt[4E - 1], 10, 105][[1]] (* Alonso del Arte, Oct 01 2011 *)
PROG
(PARI) sqrt(suminf(n=1, (1/2*n^3+1/2*n+1)/n!)); \\ Michel Marcus, Mar 09 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Alexander R. Povolotsky, Mar 06 2008
EXTENSIONS
Offset corrected R. J. Mathar, Jan 26 2009
STATUS
approved