A345929 Decimal expansion of Product_{k>=1} (1 + 1/k + 1/k^2)^2/(1 + 2/k + 3/k^2).

1, 8, 4, 8, 9, 3, 6, 1, 8, 2, 8, 5, 8, 2, 4, 4, 4, 8, 5, 2, 2, 4, 9, 2, 6, 8, 5, 5, 5, 2, 0, 8, 3, 9, 0, 5, 9, 0, 9, 2, 5, 9, 2, 5, 3, 1, 8, 9, 6, 3, 9, 7, 1, 9, 1, 8, 2, 8, 1, 4, 0, 1, 7, 3, 7, 5, 0, 2, 6, 6, 5, 6, 8, 0, 7, 9, 0, 6, 7, 7, 9, 4, 4, 6, 9, 7, 8

Offset

1,2

Links

Table of n, a(n) for n=1..87.

Jonathan M. Borwein and Robert M. Corless, Emerging Tools for Experimental Mathematics, The American Mathematical Monthly, Vol. 106, No. 10 (1999), pp. 889-909.

Formula

Equals 3*sqrt(2)*cosh(Pi*sqrt(3)/2)^2/(Pi*sinh(Pi*sqrt(2))).

Example

1.84893618285824448522492685552083905909259253189639...

Mathematica

RealDigits[3*Sqrt[2]*Cosh[Pi*Sqrt[3]/2]^2/(Pi*Sinh[Pi*Sqrt[2]]), 10, 100][[1]]

Crossrefs

Cf. A090986.

Sequence in context: A110835 A087015 A200224 * A336065 A124012 A335354

Adjacent sequences: A345926 A345927 A345928 * A345930 A345931 A345932

Keyword

nonn,cons

Author

Amiram Eldar, Jun 29 2021

Status

approved