Live data from Hacker News

A formula for the nth digit of πœ‹ and πœ‹^n

arxiv.org

41–50 of 143 posts

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#41
post #33
post #22

In "n’th digit of πœ‹ and πœ‹^n" are both n the same? In other words, for say πœ‹^50 does the formula only give me the 50th digit, or does it give me any arbitrary digit I want?

The article title says "powers of πœ‹", so presumably an arbitrary digit.

[deleted]

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#43
post #4
post #2

So does it mean that these pi-calculating competitions & record are now going to devolve to special olympiads in pointless storage capacity? What will the super computers going to do in view of this discovery? Fascinating times for humans as well as for the machines...

Ο€fs: Never worry about data again! - https://github.com/philipl/pifs

It's actually not known if pi contains every combination of digits (in any base 2 or greater) or not. It feels likely but really all we know is it's transcendental and seems pretty random from the parts we've generated.

The library of babel could be a good "useless" backing though https://libraryofbabel.info/bookmark.cgi?hnexample

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#44

Looks interesting! Does anyone know a practical application where something like this would help?

I believe it can be used to verify calculations of new digits of pi. For example, if you tell me you just computed five trillion digits of pi, I can ask you for specific digits near the end and check that they match what this formula produces

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#47
post #33
post #22

In "n’th digit of πœ‹ and πœ‹^n" are both n the same? In other words, for say πœ‹^50 does the formula only give me the 50th digit, or does it give me any arbitrary digit I want?

The article title says "powers of πœ‹", so presumably an arbitrary digit.

I’m not sure that’s right.

The abstract and text say the nth digit of \pi^n, and the worked example on page 2 uses the same n=1000 to find the thousandth digit of \pi^{1000}.

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#48
post #35

Earlier quoted context omitted.

Spoiler: it's zero, recurring.

That would make it a rational number, so we can rule that out

Exactly, the only possible "last digit" it could have (in keeping with the silly premise that it has one), is zero.

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#49

Looks interesting! Does anyone know a practical application where something like this would help?

>Does anyone know a practical application where something like this would help?

It's another way to help verify super long calculations of pi are correct, and in turn I guess one basic "practical application" of calculating pi to many digits is as part of the suite for verifying new hardware. How do you know that fancy fresh new silicon is actually crunching the numbers correctly, not producing garbage in some subtle way at enough significant digits? While there are lots and lots of checks used to avoid a repeat of hardware bugs of days past (like the forever infamous Pentium FDIV), one simple sanity check/stress test is calculating out numbers like pi a bunch of different ways to huge numbers of digits and making sure the result is always correct. If it's not there's clearly a problem somewhere.

Re: A formula for the nth digit of πœ‹ and πœ‹^n

#50
post #33

Earlier quoted context omitted.

The article title says "powers of πœ‹", so presumably an arbitrary digit.

I’m not sure that’s right. The abstract and text say the nth digit of \pi^n, and the worked example on page 2 uses the same n=1000 to find the thousandth digit of \pi^{1000}.

[deleted]
Post reply on HN