login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A292888
Decimal expansion of Product_{k>=1} (1 - exp(-3*Pi*k)).
20
9, 9, 9, 9, 1, 9, 2, 9, 3, 9, 7, 0, 0, 1, 7, 5, 5, 9, 3, 2, 4, 2, 8, 2, 6, 5, 5, 3, 2, 0, 3, 2, 2, 8, 8, 4, 6, 9, 8, 3, 4, 9, 2, 8, 0, 3, 1, 7, 2, 7, 7, 0, 3, 1, 5, 3, 2, 3, 1, 9, 2, 8, 4, 1, 3, 6, 6, 5, 7, 0, 0, 1, 7, 0, 6, 5, 2, 6, 3, 1, 3, 2, 0, 9, 3, 3, 4, 8, 9, 7, 2, 3, 7, 7, 7, 7, 1, 0, 3, 7, 5, 5, 1, 9, 6, 3
OFFSET
0,1
LINKS
Eric Weisstein's World of Mathematics, Dedekind Eta Function
Eric Weisstein's World of Mathematics, q-Pochhammer Symbol
Wikipedia, Euler function
FORMULA
Equals (5 - sqrt(3) + sqrt(2)*3^(3/4))^(1/6) * exp(Pi/8) * Gamma(1/4) / (2^(25/24) * 3^(3/8) * Pi^(3/4)).
EXAMPLE
0.999919293970017559324282655320322884698349280317277031532319284136657...
MATHEMATICA
RealDigits[(5 - Sqrt[3] + Sqrt[2]*3^(3/4))^(1/6) * E^(Pi/8) * Gamma[1/4] / (2^(25/24)*3^(3/8)*Pi^(3/4)), 10, 120][[1]]
RealDigits[QPochhammer[E^(-3*Pi)], 10, 120][[1]]
PROG
(PARI) (5 - sqrt(3) + sqrt(2)*3^(3/4))^(1/6) * exp(Pi/8) * gamma(1/4) / 2^(25/24) / 3^(3/8) / Pi^(3/4) \\ Charles R Greathouse IV, Sep 02 2024
KEYWORD
nonn,cons
AUTHOR
Vaclav Kotesovec, Sep 26 2017
STATUS
approved