A237890 Primes p such that p^2 + 4 and p^2 + 10 are also primes.

3, 7, 13, 97, 487, 613, 743, 827, 883, 1117, 1987, 2477, 2887, 3863, 4483, 5153, 5557, 5683, 5923, 5953, 6287, 7643, 7937, 8093, 9323, 10343, 12377, 13033, 13063, 14087, 14767, 15373, 16937, 17713, 17987, 18257, 19013, 19333, 19753, 19853, 20287, 20873, 21673

Offset

1,1

Links

K. D. Bajpai, Table of n, a(n) for n = 1..1300

Example

7 is prime and appears in the sequence because 7^2+4 = 53 and 7^2+10 = 59 are also primes.
97 is prime and appears in the sequence because 97^2+4 = 9413 and 97^2+10 = 9419 are also primes.

Maple

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);

Mathematica

Select[Prime[Range[5000]], PrimeQ[#^2 + 4] && PrimeQ[#^2 + 10] &]

Prog

(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

Crossrefs

Cf. A000040, A023200, A046136, A230223.

Sequence in context: A071087 A309775 A038691 * A082718 A221211 A322301

Adjacent sequences: A237887 A237888 A237889 * A237891 A237892 A237893

Keyword

nonn

Author

K. D. Bajpai, Feb 15 2014

Status

approved