A287842 Primes of the form (1 + x)^(2^y) + x^(2^y) where x is a divisor of y.

5, 17, 97, 257, 65537

Offset: 1

Author

Juri-Stepan Gerasimov, Jun 01 2017

Keywords

• nonn
• more

Examples

			97 is in this sequence because (1 + 2)^(2^2) + 2^(2^2) = 97 is prime and 2 is a divisor of 2.
		

Links

• Juri-Stepan Gerasimov, x^(y + 1) - y^x, SeqFan list, Aug 18 2014.
• Eric Weisstein's World of Mathematics, Fermat Prime.

Crossrefs

Subsequence of A285886.

Cf. A019434.

Programs

Mathematica

Sort@ Flatten@ Table[Function[{x, y}, Select[(1 + x)^(2^y) + x^(2^y), PrimeQ]] @@ {Divisors@ #, #} &@ n, {n, 12}] (* Michael De Vlieger, Jun 01 2017 *)