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%I #3 Nov 11 2010 07:34:06
%S 0,5,22,118,1803,8182,131062,524278,498820,271127480,2147483638,
%T 44060320367,967030303245,7907414671310,49672464783624,
%U 5545884378065500,125222315103997360,2305843009213693942,130613131595363896897
%N Residues of 3^(2^(p(n)-1)+1) for Mersenne numbers with prime indices.
%C Mp is prime iff 3^(2^(p(n)-1)+1) is congruent to (-9) Mod Mp. Thus M7 = 127 is prime because 3^65 Mod 127 = 118 (=127-9) while M11 = 2047 is composite because 3^1025 Mod 2047 <> 2038.
%H Dennis Martin, <a href="/A131460/b131460.txt">Table of n, a(n) for n = 1..100</a>
%F a(n) = 3^(2^(p(n)-1)+1) Mod 2^p(n)-1
%e a(5) = 3^(2^(11-1)+1) Mod 2^11-1 = 3^1025 Mod 2047 = 1803
%Y Cf. A095847, A001348, A131458, A131459, A131461, A131462, A131463.
%K nonn
%O 1,2
%A Dennis Martin (dennis.martin(AT)dptechnology.com), Jul 13 2007, Jul 20 2007
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