This is why Math is...
sometimes frustrating but usually fascinating.
Here is the famous Ramanujan Summation:
1+2+3+4+5+........... = (-1/12)
It is absurd and incorrect within the confines of mathematical Series studied under calculus. However this infinitely weird result finds a lot of application in String theory.
Here is a copy of one of the pages from Ramanujan's letter to G.H.Hardy, where this intriguing series is mentioned.
Super note!