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A237890 Primes p such that p^2 + 4 and p^2 + 10 are also primes. 8
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 18 15:13 EDT 2021. Contains 345120 sequences. (Running on oeis4.)