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%I #11 Apr 25 2016 11:50:04
%S 3,7,3,5,3,5,83,5,7,43,11,23,3,71,47,97,109,13,19,17,53,83,97,53,43,
%T 97,5,3,43,17,19,13,307,103,293,13,11,457,113,317,67,47,311,127,281,3,
%U 97,13,127,1223,61,307,29
%N Smallest odd prime Q such that Q^2*2^prime(n)-1 is a prime number starting with n=2.
%H Pierre CAMI, <a href="/A252734/b252734.txt">Table of n, a(n) for n = 2..1800</a>
%e 3^2*2^3-1=71 prime so a(2)=3.
%e 7^2*2^5-1=1567 prime so a(3)=7.
%t Table[k=3; While[Not[PrimeQ[k^2*2^Prime[n]-1]],k=NextPrime[k]]; k,{n,2,100}] (* _Vaclav Kotesovec_, Dec 21 2014 *)
%o (PFGW & SCRIPT)
%o SCRIPT
%o DIM n,1
%o DIM q
%o OPENFILEOUT myf,a(n).txt
%o LABEL loop1
%o SET n,n+1
%o SET q,1
%o LABEL loop2
%o SET q,q+1
%o PRP p(q)^2*2^p(n)-1
%o IF ISPRP THEN GOTO a
%o GOTO loop2
%o LABEL a
%o WRITE myf,q
%o GOTO loop1
%Y Cf. A252733.
%K nonn
%O 2,1
%A _Pierre CAMI_, Dec 21 2014
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