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%I #16 Dec 18 2017 11:46:55
%S 191,5399,1259393
%N Odd primes p such that tau(p) is congruent to (p-1)/2 (mod p), where tau is the Ramanujan tau function (A000594).
%C a(4) > 10^7.
%C There is no odd prime p (< 10^7) such that tau(p) is congruent to (p+1)/2 (mod p).
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TauFunction.html">Tau Function.</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Ramanujan_tau_function">Ramanujan tau function</a>
%e tau(191) = 2762403350592 and 2762403350592 == 95 mod 191, so a(1) = 191.
%e tau(5399) = -616400667743946780600 and -616400667743946780600 == 2699 mod 5399, so a(2) = 5399.
%e tau(1259393) = -600367974333827988240021654527358 and -600367974333827988240021654527358 == 629696 mod 1259393, so a(3) = 1259393.
%Y Cf. A000594, A007659, A076847 (tau(p)), A193855, A273650, A273651, A295645.
%K nonn,more
%O 1,1
%A _Seiichi Manyama_, Dec 16 2017
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