# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a237890 Showing 1-1 of 1 %I A237890 #8 Feb 17 2014 23:46:47 %S A237890 3,7,13,97,487,613,743,827,883,1117,1987,2477,2887,3863,4483,5153, %T A237890 5557,5683,5923,5953,6287,7643,7937,8093,9323,10343,12377,13033,13063, %U A237890 14087,14767,15373,16937,17713,17987,18257,19013,19333,19753,19853,20287,20873,21673 %N A237890 Primes p such that p^2 + 4 and p^2 + 10 are also primes. %H A237890 K. D. Bajpai, Table of n, a(n) for n = 1..1300 %e A237890 7 is prime and appears in the sequence because 7^2+4 = 53 and 7^2+10 = 59 are also primes. %e A237890 97 is prime and appears in the sequence because 97^2+4 = 9413 and 97^2+10 = 9419 are also primes. %p A237890 KD := proc() local a,b,d; a:=ithprime(n); b:=a^2+4; d:=a^2+10; if isprime (b) and isprime(d) then RETURN (a); fi; end: seq(KD(), n=1..5000); %t A237890 Select[Prime[Range[5000]], PrimeQ[#^2 + 4] && PrimeQ[#^2 + 10] &] %o A237890 (PARI) s=[]; forprime(p=2, 25000, if(isprime(p^2+4) && isprime(p^2+10), s=concat(s, p))); s \\ _Colin Barker_, Feb 15 2014 %Y A237890 Cf. A000040, A023200, A046136, A230223. %K A237890 nonn %O A237890 1,1 %A A237890 _K. D. Bajpai_, Feb 15 2014 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE