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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A107312 Primes p such that p + 2 and p^2 + 2^2 are primes. 1
 3, 5, 17, 137, 347, 827, 2087, 2687, 3557, 3917, 4517, 4967, 5477, 5657, 5867, 6827, 7457, 7547, 7877, 8087, 8537, 8597, 10037, 10427, 10937, 12107, 12377, 13397, 13877, 16067, 17837, 17987, 19427, 19697, 20507, 20717, 20807, 22367, 22637 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes are lesser twins. Except a(1) and a(2), all a(n) == 7(mod 10). LINKS Edward Jiang, Table of n, a(n) for n = 1..1000 MAPLE select(p -> isprime(p) and isprime(p+2) and isprime(p^2+4), [seq(2*i+1, i=1..10000)]); # Robert Israel, Aug 11 2014 MATHEMATICA Select[Prime[Range[3000]], PrimeQ[ #+2]&&PrimeQ[ #^2+4]&] PROG (MAGMA) [p: p in PrimesUpTo(25000)|  IsPrime(p+2) and IsPrime(p^2+4)] // Vincenzo Librandi, Jan 29 2011 (PARI) a(n)=isprime(n) && isprime(n+2) && isprime(n^2+4) \\ Edward Jiang, Aug O8 2014 CROSSREFS Cf. A045637. Sequence in context: A288376 A096178 A348430 * A083213 A171271 A056826 Adjacent sequences:  A107309 A107310 A107311 * A107313 A107314 A107315 KEYWORD nonn AUTHOR Zak Seidov, May 21 2005 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 August 11 12:12 EDT 2022. Contains 356065 sequences. (Running on oeis4.)