%I A050259
%S A050259 1,4700063497,3468371109448915,8365386194032363,10991007971508067
%N A050259 Numbers n such that 2^n == 3 (mod n).
%C A050259 No other terms below 1.1*10^16.
%C A050259 Terms were computed: a(2) by the Lehmers, a(3) by Max Alekseyev, a(4) 
               and a(5) by Joe K. Crump, a(?) = 63130707451134435989380140059866138830623361447484274774099906755 
               by P.-L. Montgomery.
%C A050259 a(2) was first computed by the Lehmers.
%D A050259 Mauldin, R. Daniel; Ulam, S. M.; Mathematical problems and games. Adv. 
               in Appl. Math. 8 (1987), 281-344. [From N. J. A. Sloane, Jul 30 2009]
%H A050259 Joe K. Crump, <a href="http://www.immortaltheory.com/NumberTheory/2nmodn.htm">
               2^n mod n</a>
%H A050259 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               2.html">Link to a section of The World of Mathematics.</a>
%Y A050259 Cf. A036236, A015940.
%Y A050259 Sequence in context: A034916 A124977 A128172 this_sequence A015384 A072018 
               A158726
%Y A050259 Adjacent sequences: A050256 A050257 A050258 this_sequence A050260 A050261 
               A050262
%K A050259 nonn,more,hard
%O A050259 1,2
%A A050259 Eric Weisstein (eric(AT)weisstein.com)
%E A050259 a(1)-a(5) certified by Max Alekseyev, Jan 27 2007, Apr 27 2009.