Pillai prime
(another Prime Pages' Glossary entries)
The Prime Glossary
Glossary: Prime Pages: Top 5000: 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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