A175283 Numbers k with the property that k and k^2 + 3k+9 are primes.

2, 7, 11, 17, 23, 29, 31, 37, 43, 73, 101, 107, 127, 163, 179, 197, 239, 277, 281, 317, 331, 359, 367, 421, 457, 463, 487, 541, 569, 613, 617, 619, 661, 709, 739, 773, 787, 809, 823, 877, 941, 947, 953, 991, 1019, 1031, 1033, 1039, 1051, 1087, 1163, 1187

Offset: 1

Author

Zak Seidov, Mar 21 2010

Keywords

• nonn

Comments

Or, primes in A175282.

Crossrefs

Cf. A005471, A175281, A175282.

Programs

Magma

[ n: n in [0..1250] | IsPrime(n) and IsPrime(n^2+3*n+9)] // Vincenzo Librandi, Jan 30 2011

Mathematica

Select[Prime[Range[400]],PrimeQ[ #^2+3*#+9]&]