Purdue University's Louis De Branges de Bourcia claimed to have a proof for this in June 2004.  It initially began with Euler's definition of the related function, which he evaluated only at real numbers and which he investig
Purdue University's Louis De Branges de Bourcia claimed to have a proof for this in June 2004.  It initially began with Euler's definition of the related function, which he evaluated only at real numbers and which he investigated at Bernoulli numbers to show that the sum of the squares of the inverses of the integers equals pi over two.  Its namesake extended that function, the zeta function, over the complex plane and made, FTP, what hypothesis that all the non-trivial zeros of this function would lie along the critical line, having real part equal to one half?
Purdue University's Louis De Branges de Bourcia claimed to have a proof for this in June 2004.  
Riemann hypothesis