OFFSET
1,1
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..10000
J. M. Borwein and P. B. Borwein, Strange Series and High Precision Fraud, The American Mathematical Monthly, Vol. 99, No. 7 (1992), pp. 622-640.
FORMULA
Approximately 196669/37303, correct to 88 digits: see Example 4.2 (c) in Borwein and Borwein (1992), pp. 634-635, although there is a typo in the denominator of the summands (6^k instead of 2^k).
EXAMPLE
5.2722033080449293622496850119293354421896362222877516553628...
MATHEMATICA
First[RealDigits[Sum[IntegerLength[6^k]^2/2^k, {k, 350}], 10, 100]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Paolo Xausa, May 17 2024
STATUS
approved