# Pillai prime

A**Pillai prime**is a prime number

*p*for which there is an integer

*n*> 0 such that

*n*! is one less than a multiple of

*p*, while

*p*is not one more than a multiple of

*n*. It is named after the mathematician Subbayya Sivasankaranarayana Pillai (1901-1950) who proved that there are infinitely many such primes. The sequence starts 23, 29, 59, 61, 67, 71, ....

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