OFFSET
2,1
LINKS
Herman P. Robinson, Mathematical Constants. p. 181.
Eric Weisstein's World of Mathematics, Planck's Radiation Function
FORMULA
(W(-5/e^5) + 5)^5/(-1 + e^(W(-5/e^5) + 5)), where W is the LambertW function (ProductLog).
Equals A245261/(15/Pi^4).
EXAMPLE
21.201435660549920740087797953797467440281362889...
MATHEMATICA
RealDigits[(ProductLog[-5/E^5] + 5)^5/(-1 + E^(ProductLog[-5/E^5] + 5)), 10, 104] // First
CROSSREFS
KEYWORD
AUTHOR
Jean-François Alcover, Feb 20 2015
STATUS
approved