OFFSET
0,1
FORMULA
Equals 2 - cos(1) - 2 sin(1).
EXAMPLE
-0.2232442754839327307059412507035746029774...
MATHEMATICA
s = Sum[(-1)^k k/((k + 1) (2 k)!), {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, May 01 2024
STATUS
approved