Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #6 Oct 15 2013 22:32:17
%S 19,43,67,31,2087,29,31,89,6359,31,29,19,31,199,1429,29,229,641,31,41,
%T 29,31,19,89,31,29,41,31,29573,38729,29,89,389,19,43103,29,31,67,929,
%U 31,29,38729,31,89,19,29,146543,41,31,1193,29,31,5077,53,31,19,449,31,701
%N a(n)=prime(x) is the smallest prime such that 1+(2^(12n+9))*prime(x) is divisible by prime(x+1).
%F a(n)=Min{p[x]; Mod[1+[2^(12n+9)].p[x], p[x+1]]=0}; a(n)=A087985[2^(9+12n)]
%e n = 4: exponent = 4.12+9 = 57, 2^57 = 144115188075855872; a(4) = 2087 = p[315] because 1+144115188075855872.2087 = 300768397514311204865 = 2089.5.23.2593.14669.32914927 = p[316].m
%e Must a solution always exist? Difficult exponents are 193,253,...
%Y Cf. A087985.
%K nonn
%O 0,1
%A _Labos Elemer_, Oct 06 2003
%E More terms from _David Wasserman_, Jun 17 2005