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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A118915 Primes p such that (p^2 + 5)/6 is prime. 16
 5, 13, 19, 23, 37, 41, 89, 113, 127, 131, 139, 149, 167, 197, 229, 233, 239, 251, 271, 359, 373, 401, 433, 449, 463, 503, 523, 541, 607, 631, 643, 653, 701, 719, 743, 769, 811, 827, 877, 881, 887, 919, 967, 971, 1009, 1013, 1021, 1093, 1097, 1283, 1301 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For all primes q>3, we have q=6k+-1 for some k, which makes it easy to show that 6 divides q^2+5. (n^2+5)/6 is an integer for all primes except 2 and 3. - Michael B. Porter, Apr 14 2010 LINKS Table of n, a(n) for n=1..51. PROG (PARI) isA118915(n)=if(n^2%6==1, isprime(n)&&isprime((n^2+5)/6), 0) \\ Michael B. Porter, Apr 14 2010 CROSSREFS Cf. A109953 (primes p such that (p^2+1)/3 is prime), A118918 (primes p such that (p^2+11)/12 is prime). Sequence in context: A156111 A162174 A171603 * A084442 A023270 A279765 Adjacent sequences: A118912 A118913 A118914 * A118916 A118917 A118918 KEYWORD nonn AUTHOR T. D. Noe, May 05 2006 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 September 14 03:19 EDT 2024. Contains 375911 sequences. (Running on oeis4.)