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A114941
Decimal expansion of the infinite sum Sum_{k>=1} cos(k)/k!.
1
1, 4, 3, 8, 3, 5, 6, 4, 3, 7, 9, 1, 6, 4, 0, 3, 2, 5, 9, 0, 6, 6, 4, 7, 3, 4, 3, 9, 6, 7, 9, 0, 2, 0, 2, 8, 0, 3, 0, 4, 5, 9, 0, 9, 3, 5, 8, 5, 5, 3, 0, 0, 3, 2, 3, 9, 3, 2, 0, 6, 1, 3, 0, 0, 6, 5, 7, 4, 5, 9, 9, 8, 7, 4, 2, 3, 6, 2, 1, 8, 5, 1, 6, 2, 6, 3, 0, 1, 5, 1, 5, 1, 6, 9, 0, 2, 9, 3, 8, 0, 0, 3, 1, 1
OFFSET
0,2
FORMULA
From Amiram Eldar, Jul 19 2020: (Start)
Equals e^cos(1) * cos(sin(1)) - 1.
Equals cos(sin(1)) * (cosh(cos(1)) + sinh(cos(1))) - 1.
Equals (e^(e^i) + e^(e^(-i)))/2 - 1. (End)
EXAMPLE
0.143835643791640325906...
MATHEMATICA
RealDigits[Sum[N[Cos[i], 400]/i!, {i, 1, 300}]][[1]] (*which is accurate to 300 digits*) (* corrected by Harvey P. Dale, Nov 29 2011 *)
PROG
(PARI) suminf(k=1, cos(k)/k!) \\ Michel Marcus, Jul 19 2020
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
STATUS
approved