Ulam spiral

English edit

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Ulam spiral

Ulam spiral of size 201×201. Black dots represent prime numbers. Diagonal, vertical, and horizontal lines with a high density of prime numbers are clearly visible.

Etymology edit

Devised by mathematician Stanislaw Ulam in 1963.

Noun edit

Ulam spiral (plural Ulam spirals)

(mathematics) A graphical depiction of the set of prime numbers, constructed by writing the positive integers in a square spiral and specially marking the primes.