The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A175283 Numbers k with the property that k and k^2 + 3k+9 are primes. 1
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Or, primes in A175282. LINKS 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 5 14:51 EST 2022. Contains 358588 sequences. (Running on oeis4.)