OFFSET
0,2
LINKS
Aubrey J. Kempner, On Transcendental Numbers, Transactions of the American Mathematical Society, volume 17, number 4, October 1916, pages 476-482.
FORMULA
Equals -Sum_{k>=1} mu(2*k)/(9^k - 1), where mu is the Möbius function (A008683). - Amiram Eldar, Jul 12 2020
EXAMPLE
0.123609229144306327782...
MATHEMATICA
RealDigits[ N[ Sum[1/9^(2^n), {n, 0, Infinity}], 110]][[1]]
PROG
(PARI) suminf(n=0, 1/9^(2^n)) \\ Michel Marcus, Nov 11 2020
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
Robert G. Wilson v, Dec 11 2002
STATUS
approved