Find a counterexample to the following:

If n is a natural number then n^2 + n + 41 is a prime number.

I guess the only way to do this is by trial and error?

Question

Find a counterexample to the following:

If n is a natural number then n^2 + n + 41 is a prime number.

I guess the only way to do this is by trial and error?

geerky42 · Answer

Let n = 41 then you can factor 41 out.

cwrw238 · Answer

yes!  - that didn't occur to me!!!!

cwrw238 · Answer

obvious really!!

ganeshie8 · Answer

this form might make it obvious
$$n(n+1) + 41$$

anonymous · Answer

can someone pls help me

ganeshie8 · Answer

this was widely believed to be a prime generating function until Euler gave counter example putting an end to the conjecture

ganeshie8 · Answer

history behind this quadratic is pretty interesting

ikram002p · Answer

yeah there is greats formula ppl thought they are prime :D

cwrw238 · Answer

yes - i've been reading about Euler recently - he was amazing. He could do complex problems in his head. A lot of his best work was done after he lost his sight.

ganeshie8 · Answer

http://gyazo.com/7ed757c91911de25b7fb85410ce6d5e3

ikram002p · Answer

great things cant be seen by eyes , only whom open their  hears and minds can  see it !

ikram002p · Answer

like eluer xD

perl · Answer

he did a surgery himself on his eye, which was successful but later he got an infection (they did not know about sterilization)

ikram002p · Answer

he had mathematician ego :D

perl · Answer

:)

anonymous · Answer

Didn't newton do a surgery on his own eye to, wait he put a needle on his eye to see what would happen to light...silly geniuses.

perl · Answer

yes, he put a needle in his eye. he also stared the sun

cwrw238 · Answer

- not too clever in that respect!!

anonymous · Answer

I think that was Gallileo who stared at the sun

perl · Answer

many scientists died or received harm in the pursuit of knowledge, such as the caries and their experiments on radium and polonium

perl · Answer

i thought it was newton :) woops

anonymous · Answer

Nope :d Newton knows!

ikram002p · Answer

well , im sure he dint do it again :D

ganeshie8 · Answer

lol reminds me of a story... there is a demigod in hindu mythology who flied to the setting sun thinking of it as a red apple and screwed up his lips ;) http://media1.santabanta.com/full1/Bollywood%20Movies/Hanuman/han1v.jpg

anonymous · Answer

Aw :3

ikram002p · Answer

cute lol

anonymous · Answer

I've heard that story before to xD

cwrw238 · Answer

lol