A091567 Primes p such that p^2-p-1 is prime.

3, 5, 7, 11, 17, 29, 31, 47, 61, 67, 71, 97, 101, 127, 131, 139, 149, 181, 197, 241, 269, 307, 331, 359, 379, 397, 409, 419, 421, 449, 457, 479, 487, 491, 599, 607, 617, 619, 641, 647, 677, 709, 751, 787, 839, 857, 907, 947, 967, 977, 997, 1051, 1061, 1091

Offset: 1

Author

T. D. Noe, Jan 21 2004

Keywords

• nonn

References

• M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
• Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A053182 (p^2+p+1 prime), A053184 (p^2+p-1 prime), A065508 (p^2-p+1 prime).

Cf. A091568 (corresponding primes of the form p^2-p-1).

Programs

Mathematica

Select[Prime[Range[250]], PrimeQ[ #^2-#-1]&] (* Alexander Adamchuk, Jul 27 2006 *)

PARI

isA091567(n)=isprime(n) && isprime(n^2-n-1) \\ Michael B. Porter, May 12 2010