WOLFRAM|DEMONSTRATIONS PROJECT

The Prime-Product Ratio of Ramanujan

​
n
10
100
500
1000
The great Indian mathematician Srinivasa Ramanujan (1887–1920) discovered a startling relation for a product involving prime numbers:
∞
∏
i=1
2
p
i
+1
2
p
i
-1
=
5
2
.