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A240838 Primes p such that prime(p) + 2*p^2 is prime. 0
2, 3, 5, 13, 41, 43, 139, 173, 227, 239, 359, 463, 541, 691, 743, 761, 821, 823, 827, 887, 1021, 1117, 1289, 1427, 1489, 1637, 1723, 1933, 1999, 2081, 2287, 2309, 2719, 2791, 2833, 2843, 2953, 3329, 3541, 3803, 3823, 3929, 4003, 4007, 4079, 4139, 4297, 4451, 4561, 4597, 4691, 4703, 4817, 4931, 4943 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The associated primes are: 11, 23, 41, 379, 3541, ...
LINKS
EXAMPLE
2 is in this sequence because 2 and prime(2) + 2*2^2 = 3 + 8 = 11 are both prime.
MATHEMATICA
Select[Prime[Range[700]], PrimeQ[Prime[#]+2#^2]&] (* Harvey P. Dale, Mar 19 2018 *)
PROG
(Magma) [n: n in {1..5000} | IsPrime(n) and IsPrime(s) where s is (2*n^2 + NthPrime(n))];
(PARI) isok(p) = isprime(p) && isprime(prime(p) + 2*p^2); \\ Michel Marcus, Apr 13 2014
CROSSREFS
Sequence in context: A013013 A087362 A038560 * A238814 A000756 A192241
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)