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 A065376 Primes of the form p + k^2, p prime and k > 0. 3

%I

%S 3,7,11,17,19,23,29,41,43,47,53,59,67,71,73,79,83,89,97,101,103,107,

%T 109,113,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,

%U 211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307

%N Primes of the form p + k^2, p prime and k > 0.

%C Conjectured to contain all primes > 7549. - _Robert Israel_, Sep 03 2014

%e a(3) = 11 = 2 + 3^2 = 7 + 2^2.

%p N = 1000: # to get all entries <= N

%p Primes:= select(isprime, {\$1..N}):

%p Primes intersect {seq(seq(p + k^2, p = Primes),k=1..floor(sqrt(N)))}; # _Robert Israel_, Sep 03 2014

%o (PARI) lista(nn) = {forprime(p=2, nn, forprime(q=2, p-1, if (issquare(p-q), print1(p, ", "); break;);););} \\ _Michel Marcus_, Sep 03 2014

%Y Cf. A000040, A000290, A065377.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Nov 03 2001

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Last modified August 8 14:59 EDT 2022. Contains 356009 sequences. (Running on oeis4.)