%I A005937 M5246
%S A005937 35,185,217,301,481,1105,1111,1261,1333,1729,2465,2701,2821,3421,3565,
%T A005937 3589,3913,4123,4495,5713,6533,6601,8029,8365,8911,9331,9881,10585,
%U A005937 10621,11041,11137,12209,14315,14701,15841,16589,17329,18361,18721
%N A005937 Pseudoprimes to base 6.
%C A005937 Theorem: If both numbers q and 2q-1 are primes and n=q*(2q-1) then 6^(n-1)==1 
               (mod n)(n is in the sequence) iff q is of the form 12k+1. 2701,18721,
               49141,104653,226801,665281,... are such terms. This sequence is a 
               subsequence of A122783. - Farideh Firoozbakht (mymontain(AT)yahoo.com), 
               Sep 12 2006
%D A005937 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005937 R. K. Guy, Unsolved Problems in Number Theory, A12.
%H A005937 R. J. Mathar, <a href="b005937.txt">Table of n, a(n) for n=1..118</a>
%H A005937 <a href="Sindx_Ps.html#pseudoprimes">Index entries for sequences related 
               to pseudoprimes</a>
%t A005937 Select[Range[20000], ! PrimeQ[ # ] && Mod[6^(# - 1), # ] == 1 &] - Farideh 
               Firoozbakht (mymontain(AT)yahoo.com), Sep 12 2006
%Y A005937 Cf. A122783.
%Y A005937 Sequence in context: A015219 A033851 A101954 this_sequence A007329 A101628 
               A064013
%Y A005937 Adjacent sequences: A005934 A005935 A005936 this_sequence A005938 A005939 
               A005940
%K A005937 nonn
%O A005937 1,1
%A A005937 N. J. A. Sloane (njas(AT)research.att.com).
%E A005937 More terms from Farideh Firoozbakht (mymontain(AT)yahoo.com), Sep 12 
               2006