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

1,1

Comments

Or, primes in A175282.

Links

Table of n, a(n) for n=1..52.

Mathematica

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

Prog

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

Crossrefs

Cf. A005471, A175281, A175282.

Sequence in context: A356190 A168421 A038942 * A124136 A156828 A019385

Adjacent sequences: A175280 A175281 A175282 * A175284 A175285 A175286

Keyword

nonn

Author

Zak Seidov, Mar 21 2010

Status

approved