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A295219
Decimal expansion of Product_{n>=1} n*sin(1/n).
2
7, 5, 5, 3, 6, 3, 3, 8, 8, 5, 1, 8, 5, 7, 3, 2, 1, 4, 0, 6, 3, 3, 6, 4, 9, 8, 6, 1, 7, 0, 4, 7, 6, 5, 5, 3, 5, 9, 6, 1, 2, 9, 6, 3, 6, 7, 9, 2, 1, 3, 0, 1, 4, 2, 5, 5, 7, 0, 2, 2, 5, 0, 4, 3, 3, 3, 6, 2, 5, 9, 4, 1, 6, 7, 5, 7, 8, 9, 5, 9, 4, 0, 9, 5, 8, 0, 1, 5
OFFSET
0,1
FORMULA
Equals 1*sin(1/1) * 2*sin(1/2) * 3*sin(1/3) * 4*sin(1/4) * 5*sin(1/5) * ...
From Amiram Eldar, Jul 30 2023: (Start)
Equals exp(Sum_{k>=1} 2^(2*k-1)*(-1)^k*B(2*k)*zeta(2*k)/(k*(2*k)!)), where B(k) is the k-th Bernoulli number.
Equals exp(-Sum_{k>=1} zeta(2*k)^2/(k*Pi^(2*k))). (End)
EXAMPLE
0.75536338851857321406336498617047655...
MAPLE
evalf(Product(n*sin(1/n), n = 1..infinity), 120); # Vaclav Kotesovec, Jun 23 2021
PROG
(PARI)
\\ Set the precision at least twice than the
\\ number of desired correct decimal digits
default(realprecision, 200); \\ To get the first 100 digits right
exp(-sumpos(n=1, -log(n*sin(1/n))))
CROSSREFS
Cf. A118817.
Sequence in context: A258042 A340710 A289003 * A138313 A138312 A152115
KEYWORD
nonn,cons
AUTHOR
Michal Paulovic, Nov 17 2017
EXTENSIONS
Terms corrected by Jinyuan Wang, Jul 21 2020
STATUS
approved