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A334366
Decimal expansion of Sum_{k>=0} 1/(4*k)!!.
1
1, 1, 2, 7, 6, 2, 5, 9, 6, 5, 2, 0, 6, 3, 8, 0, 7, 8, 5, 2, 2, 6, 2, 2, 5, 1, 6, 1, 4, 0, 2, 6, 7, 2, 0, 1, 2, 5, 4, 7, 8, 4, 7, 1, 1, 8, 0, 9, 8, 6, 6, 7, 4, 8, 3, 6, 2, 8, 9, 8, 5, 7, 3, 5, 1, 8, 7, 8, 5, 8, 7, 7, 0, 3, 0, 3, 9, 8, 2, 0, 1, 6, 3, 1, 5, 7, 1, 2, 0, 6, 5, 7, 8, 2, 1, 7, 8, 0, 4, 9, 5, 1, 4, 6, 4, 5, 2, 1, 3, 7
OFFSET
1,3
COMMENTS
This constant is transcendental.
FORMULA
Equals cosh(1/2).
Equals Product_{k>=0} 1 + 1/((2*k+1)*Pi)^2. - Amiram Eldar, Jul 16 2020
EXAMPLE
1/(2^0*0!) + 1/(2^2*2!) + 1/(2^4*4!) + ... = 1.1276259652063807852...
MATHEMATICA
RealDigits[Cosh[1/2], 10, 110] [[1]]
PROG
(PARI) cosh(1/2) \\ Michel Marcus, Apr 25 2020
KEYWORD
nonn,cons
AUTHOR
Ilya Gutkovskiy, Apr 24 2020
STATUS
approved