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%I A092474 #6 Oct 04 2012 11:26:26
%S A092474 3,3,7,7,7,7,37,37,163,163,163,163,163,163,163,163,163,163,163
%N A092474 a(n) is the first term in a sequence of primes such that a(n)+4m^2 is also prime for m = 1 to n.
%C A092474 a(1) starts sequence A023200; a(2) starts sequence A049492. (I've searched up to 2000000 but haven't yet found the terms from a(20) onward.)
%e A092474 a(5) = 7.
%e A092474 7+4(1^2) = 7+4(1) = 7+4 = 11 which is prime.
%e A092474 7+4(2^2) = 7+4(4) = 7+16 = 23 which is prime.
%e A092474 7+4(3^2) = 7+4(9) = 7+36 = 43 which is prime.
%e A092474 7+4(4^2) = 7+4(16) = 7+64 = 71 which is prime.
%e A092474 7+4(5^2) = 7+4(25) = 7+100 = 107 which is prime.
%t A092474 Flatten[Table[Select[Prime[Range[100]],And@@PrimeQ[Table[#+4n^2,{n,i}]]&,1],{i,19}]] (* _Harvey P. Dale_, Oct 04 2012 *)
%K A092474 nonn
%O A092474 1,1
%A A092474 _Ray G. Opao_, Mar 25 2004

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