That picture is upside down. - User 4 ∑ n = 0 ∞ ( − 1 ) n ( 2 n + 1 ) − 1 {\displaystyle \scriptstyle 4\sum _{n=0}^{\infty }(-1)^{n}(2n+1)^{-1}} 00:58, 6 March 2009 (EST)
