The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A236688 Primes p such that prime(p^2) + 2 is also prime. 5
 7, 53, 83, 107, 149, 223, 367, 509, 701, 769, 853, 971, 1039, 1229, 1283, 1327, 1373, 1381, 1439, 1447, 1459, 1783, 1873, 1973, 2237, 2243, 2269, 2339, 2347, 2437, 2459, 2521, 2531, 2797, 2857, 3001, 3391, 3413, 3461, 3583, 3593, 3631, 3659, 3769, 3889, 3947 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS K. D. Bajpai, Table of n, a(n) for n = 1..1119 EXAMPLE 7 is prime and appears in the sequence: prime(7^2) = 227 and 227+2 = 229, which is also prime. 53 is prime and appears in the sequence: prime(53^2) = 25469 and 25469+2 = 25471, which is also prime. MAPLE KD := proc() local a, b; a:=ithprime(n); b:=ithprime(a^2)+2; if isprime (b) then RETURN (a); fi; end: seq(KD(), n=1..700); PROG (PARI) default(primelimit, 2^31) s=[]; forprime(p=2, 4000, if(isprime(prime(p^2)+2), s=concat(s, p))); s \\ Colin Barker, Jan 30 2014 CROSSREFS Cf. A000040, A234695, A236119. Sequence in context: A301485 A224501 A241487 * A239941 A253123 A141911 Adjacent sequences:  A236685 A236686 A236687 * A236689 A236690 A236691 KEYWORD nonn AUTHOR K. D. Bajpai, Jan 29 2014 STATUS approved

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

Last modified August 6 12:33 EDT 2020. Contains 336246 sequences. (Running on oeis4.)