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A173473
n-th prime^2-2*n is prime.
2
1, 2, 3, 4, 6, 10, 15, 16, 19, 22, 24, 28, 31, 46, 48, 49, 61, 66, 70, 88, 90, 91, 93, 94, 96, 97, 111, 114, 118, 126, 130, 136, 141, 157, 159, 160, 163, 171, 177, 196, 199, 201, 210, 211, 213, 216, 225, 238, 243, 255, 258, 279, 294, 300, 306, 309, 312, 315, 324, 330
OFFSET
1,2
COMMENTS
Numbers n such that A001248(n)-A005843(n+1)=prime.
LINKS
EXAMPLE
1 is in the sequence because (1st prime)^2-2*1=2, which is prime;
2 is in the sequence because (2nd prime)^2-2*2=5, which is prime.
MATHEMATICA
Select[Range[4000], PrimeQ[Prime[#]^2 - 2 #] &] (* Vincenzo Librandi, Apr 15 2014 *)
PROG
(PARI) isok(n) = isprime(prime(n)^2 - 2*n); \\ Michel Marcus, Apr 15 2014
(Magma) [n: n in [0..400] | IsPrime(NthPrime(n)^2-2*n)]; // Vincenzo Librandi, Apr 15 2014
CROSSREFS
Sequence in context: A240057 A279467 A094861 * A288807 A097699 A086990
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from R. J. Mathar, Mar 01 2010
STATUS
approved