A057908 Numbers n such that 4^n - n is prime.

1, 3, 5, 35, 95, 1323, 24747

Offset: 1

Author

Robert G. Wilson v, Nov 16 2000

Keywords

• nonn
• more

Comments

a(8) > 2*10^5. - Robert Price, Feb 11 2014

Programs

Mathematica

Do[ If[ PrimeQ[ 4^n - n ], Print[ n ] ], {n, 0, 3000} ]

PARI

for(k=1,10^6,if(ispseudoprime(4^k-k),print1(k,", "))); /* Joerg Arndt, Apr 07 2013 */

Extensions

a(7) from Robert Price, Feb 11 2014