[Updated 3.15 with this delicious photo and comment.]

From Iowahawk on Twitter (@iowahawkblog)

Correction: Happy lim[n→∞] 2^4n / (n * (2n! / (2*(n!)))^2) Day

#PiDay How to bake your own converging pi in Excel:

1. let cell A1 = value of n
2. in cell B1, enter the formula =EXP(4*A1*LN(2) – LN(A1) – (2*(GAMMALN(2*A1+1) – 2* GAMMALN(A1+1))))
3. enter larger and larger values for n in cell A1, or create a column series

And voila: convergence through n=20 #PiDay

[A small explanation]

@BunceHoratio it’s a handy dandy function for formulas that involve factorials.

n! = Gamma(n+1) = exp(ln(Gamma(n+1)), or in Excel parlance =exp(GammaLn(n+1))

[But there’s a problem via David Rinaldo @valid_android]

@iowahawkblog This breaks around n=20000000000000 says 2.7 (yes I know why)

[Mr. Hawk replies]

@Valid_Android Because Bill Gates is a punkass bitch

@triadaxiom Blame Microsoft’s shitty precision, not math