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First of a pair of twin primes of the form n^2+x with x<2*n, or 0 if no such prime exist.
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%I #5 Mar 31 2012 13:22:05

%S 2,5,11,17,29,41,59,71,0,107,137,149,179,197,227,269,311,347,0,419,

%T 461,521,569,599,641,0,0,809,857,0,1019,1031,1091,0,1277,1301,1427,

%U 1451,0,1607,1697,1787,1871,1949,2027,2129,2237,2309,0,2549,2657,2711,0,2969

%N First of a pair of twin primes of the form n^2+x with x<2*n, or 0 if no such prime exist.

%H Pierre CAMI, <a href="/A143509/b143509.txt">Table of n, a(n) for n = 1..10000</a>

%e 1^2+1=2 x=1, x<2*1 and 2 and 3 twin primes so a(1)=2

%e 2^2+1=5 x=1, x<2*2 and 5 and 7 twin primes so a(2)=5

%e 3^2+2=11 x=2, x<2*3 and 11 and 13 twin primes so a(3)=11

%Y Cf. A091592.

%K nonn

%O 1,1

%A _Pierre CAMI_, Aug 21 2008