= 3.14159...

Search 2 x 109 decimal digits of Pi, E, the Square Root of Two and 5 x 108 digits of Phi (the Golden Ratio) for the first occurrence of a numeric string, or display a specified number of digits from a given starting position.

Enter digits to search or start position:
Mode: Search
Display digits from start position
Constant: Pi
E
Sqr Root 2
Phi (500M)

Message:



Please enter a numeric string to search or a starting digit (no decimals or commas)



2 billion decimal digits of Pi, E, the Square Root of 2 and 500 million digits of Phi calculated with PiFast43.

About the Irrational Numbers Search Engine:

The Irrational Numbers Search Engine was originally created in 2002 just for fun. The original implementation offered Pi digits and digits for e, Phi and the Square Root of 2 were added in 2011 by popular request. Usage of the search engine has steadily increased over time, with a total of 384,022 queries in the three year period between 2010 and 2012. Usage spiked dramatically in 2013 with a total of 301,050 queries, bringing the 4 year total to 685,072!

Search History Search Types
Search Totals Searches by Type

Between 2010 and 2012, from 111 countries accessed the search engine, including numerous corporations, universities and schools across the globe. I have received a range of email from people conducting research (from the mainstream to the fringes of credibility) to Geocachers who have found ways to embed clues within the digits of Pi. It has been interesting and rewarding to see the variety of 'uses' for the search engine!

Search Locations Search Locations
Top Countries Searches by Continent

Searches during this period averaged 7.3 digits, with an average search time of 1.53 seconds. CPU time totaled 587,894 seconds, or over 163 hours!

The search engine was originally implemented as a VB6 executable called by an ASP page, using text files for input and output. That approach was a bit of a kludge, so I ported it to a VB6 class (.dll), which is called as an object. You can download the VB6 source code and executables here. The source code package was downloaded 1506 times as of 4/9/2014.

The server hosts text files for each constant containing the numeric digits to the right of the decimal point. Full scans of the files take less than 20 seconds and searches of the same file run about 25% faster due to disk I/O caching. The application runs on a Windows Server virtual machine allocated 8GB of memory which is hosted on a 2011 Mac Mini Server with a quad core i7 CPU @ 2GHz with a solid state disk, which is essential for maximum throughput.

Send me a note about how you're using the search engine, as well as any comments, suggestions or ideas, such as implementing a faster search method (eg. BCD compression!) using the contact us link at the bottom of the page.

Links:

Pi, e, the Square Root of 2 and the Golden Ratio (Phi) on Wikipedia

10,000 decimal digits of Pi, E, SqrRt2 and Phi

PiFast written by Xavier Gourdon.

The *original* Pi Search Engine that inspired this one; much faster, but only 200m digits. Good background and statistical info.

Online Encyclopedia of Integer Sequences references to this site: https://oeis.org/A232013 and https://oeis.org/A232014


The search engine has processed 898,547 queries since 01/09/2002

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