Integer sequence prime
In mathematics, an integer sequence prime is a prime number found as a member of an integer sequence. For example, the 8th Delannoy number, 265729, is prime. A challenge in empirical mathematics is to identify large prime values in rapidly growing sequences.
A common subclass of integer sequence primes are constant primes, formed by taking a constant real number and considering prefixes of its decimal representation, omitting the decimal point. For example, the first 6 decimal digits of the constant π, approximately 3.14159265, form the prime number 314159, which is therefore known as a pi-prime (sequence A005042 in the OEIS). Similarly, a constant prime based on Euler's number, e, is called an e-prime.
Other examples of integer sequence primes include:
- Cullen prime – a prime that appears in the sequence of Cullen numbers [math]\displaystyle{ a_n = n2^n+1 . }[/math]
- Factorial prime – a prime that appears in either of the sequences [math]\displaystyle{ a_n = n!-1 }[/math] or [math]\displaystyle{ b_n = n!+1 . }[/math]
- Fermat prime – a prime that appears in the sequence of Fermat numbers [math]\displaystyle{ a_n = 2^{2^n}+1 . }[/math]
- Fibonacci prime – a prime that appears in the sequence of Fibonacci numbers.
- Lucas prime – a prime that appears in the Lucas numbers.
- Mersenne prime – a prime that appears in the sequence of Mersenne numbers [math]\displaystyle{ a_n = 2^n-1 . }[/math]
- Primorial prime – a prime that appears in either of the sequences [math]\displaystyle{ a_n = n\#-1 }[/math] or [math]\displaystyle{ b_n = n\#+1 . }[/math]
- Pythagorean prime – a prime that appears in the sequence [math]\displaystyle{ a_n = 4n+1 . }[/math]
- Woodall prime – a prime that appears in the sequence of Woodall numbers [math]\displaystyle{ a_n = n2^n-1 . }[/math]
The On-Line Encyclopedia of Integer Sequences includes many sequences corresponding to the prime subsequences of well-known sequences, for example A001605 for Fibonacci numbers that are prime.
References
- Weisstein, Eric W.. "Integer Sequence Primes". http://mathworld.wolfram.com/IntegerSequencePrimes.html.
- Weisstein, Eric W.. "Constant Primes". http://mathworld.wolfram.com/ConstantPrimes.html.
- Weisstein, Eric W.. "Pi-Prime". http://mathworld.wolfram.com/Pi-Prime.html.
- Weisstein, Eric W.. "e-Prime". http://mathworld.wolfram.com/e-Prime.html.