OFFSET
1,2
COMMENTS
Of the first 10^10 terms, 5738590822 are positive and 4261262135 are negative. - Hans Havermann, Nov 27 2016
LINKS
Hans Havermann, Table of n, a(n) for n = 1..10000
Hans Havermann, A walk in base-two pi
FORMULA
a(n) = Sum_{k=1..n} (2*b(k) - 1), where b(n) is the n-th binary digit of Pi.
EXAMPLE
The first five digits of the expansion are 1, 1, 0, 0, 1.
Starting at 0, we get 0 + 1 + 1 - 1 - 1 + 1 = 1, so a(5) = 1.
CROSSREFS
KEYWORD
AUTHOR
Steven Lubars (lubars(AT)gmail.com), Oct 03 2009
STATUS
approved