# DailyDirt: Pi Math

### from the *urls-we-dig-up* dept

National Pie Day is not actually March 14th (although it really should be, if only to make it more memorable). But here's to the number, not the delicious dessert.
- Does pi contain every set of finite number sequences? The answer to that question may not be known, but the first trillion or so digits of pi appear to be statistically random -- with 0-9 appearing with even distributed frequency. [url]
- It's possible to calculate the nth digit of pi without calculating every previous digit. So the gazillionth digit of pi can be verified, if you really need to know it. [url]
- If you're thinking about coming up with a new way to calculate pi, you can check your work for the first several trillion digits. Beyond about 10 trillion digits, you're into record breaking territory, and you'll need to adopt some other strategies. [url]

Filed Under: calculations, irrational, math, numbers, pi

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Anonymous Coward,14 Feb 2013 @ 8:42pmwhat the question really is, is 'how big does the number have to be to ensure that a specific size sequence will occur.

That can easily be worked out statistically.

for example.

with a sequence of 10 digits of random numbers you have a 100% chance of finding a 1 digit sequence in that. 1 in 10 for each digit.

so if your number sequence is 9876543210 you have a 10% chance for each digit to get a match to your sequence and a 100% chance your single digit sequence can be found in the number.

if your search sequence is 23 then you only have 10 possible numbers that can follow a 2 (0123456789), so if you have a sequence or 100 numbers there would be a 100% chance of 2 occurring 10 times, and only 10 different possibilities that can follow the 2 (3 being one of them).

therefore with 10 numbers you have 100% chance of finding a sequence of 1.

with 100 numbers you have a 100% chance of finding a sequence of 2. It's very simple, the longer your required sequence the larger the initial number has to be.

of for infinite sequence of finite numbers joke.

lets try, we'll use a finite number of digits (3) we'll call them 1, 2, 3.

now according to you I can arrange that sequence an infinite number of ways !!!.. LETS TRY.. (this could take awile).

123

213

231

321

312

132

does not look infinite to me !!! yet every possible sequence is covered

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