1/(n * (n+1)) = 1/n - 1/(n+1)
1/(12) + 1/(23) + 1/(3*4) + … = 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + … = 1
Comment on Magic
grubberfly@mander.xyz 3 weeks ago
tbf, the 2nd sum is exactly the first one just multiplied by 1/2. though i get that the progression is natural, even, and odd.
the last one is definitely odd puzzling, but i cannot intuitively get the first one. how does summing the inverse of triangular number equal 2?
Collatz_problem@hexbear.net 3 weeks ago
lolcatnip@reddthat.com 3 weeks ago
It’s not saying the proof is obvious, just that the result is plausible on its face.