# Primer

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Primer
Pattern type Miscellaneous
Number of cells 2953
Bounding box 440 × 294
Discovered by Dean Hickerson
Year of discovery 1991

Primer is a pattern that was constructed by Dean Hickerson on November 1, 1991 that produces a stream of lightweight spaceships representing prime numbers. N is prime if and only if a lightweight spaceship escapes to the left of the pentadecathlon at the bottom-left corner of the pattern at generation 120 N + 100.[1][2] It was the first known pattern created that computes prime numbers, though others have since been constructed based on the same ideas.[3]

It works by using gliders to emulate a prime number sieve[4]. Lightweight spaceships that move westward are deleted by gliders that represent positive integers if the lightweight spaceship represents a multiple of that number.

 Please enable Javascript to view this LifeViewer. The pattern(click above to open LifeViewer)RLE: here Plaintext: here

## Image gallery

 The stream of spaceships representing prime numbers

## Videos

 Click to load contentPrimer outputting the prime numbers from 2 through 37

## References

1. PRIMES.LIF from Alan Hensel's lifep.zip pattern collection. Accessed on July 28, 2009.
2. four-primers.rle.gz from Golly's built-in pattern collection
3. Jason Summers (February 28, 2012). Re: The theory behind Primer? (discussion thread) at the ConwayLife.com forums
4. Sieve of Eratosthenes at Wikipedia