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%I #14 Jan 25 2021 10:27:23
%S 3,7,31,127,1279,3583,5119,6143,8191,81919,131071,524287,14680063,
%T 109051903,654311423,738197503,2147483647,21474836479,51539607551,
%U 824633720831,13743895347199,26388279066623,246290604621823
%N Let t(x) be the highest power of 2 which divides x+1. Then a(1)=3; a(n) is the least prime p for which t(p) > t(a(n-1)).
%H M. F. Hasler, <a href="/A084924/b084924.txt">Table of n, a(n) for n = 1..100</a>
%e a(5)=1279 because t(a(4))=7 and 1279 is the least prime with t(p)>7.
%o (PARI) a=vector(50); a[1]=3;for(i=2,length(a), j=k=2^(factor(a[i-1]+1,2)[1,2]+1); while(! isprime(j-1),j+=k);a[i]=j-1); a \\ _M. F. Hasler_, Mar 15 2007
%K nonn
%O 1,1
%A _Shane Findley_, Jul 15 2003
%E Edited by _Don Reble_, May 08 2004
%E More terms from _M. F. Hasler_, Mar 15 2007
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