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%I #3 May 01 2013 21:12:46
%S 21,217,3937,1040257,1073602561,68718821377,1125897758834689,
%T 4951760154835678088235319297,
%U 1427247692705959880439315947500961989719490561
%N Products of 2 successive Mersenne primes.
%C Subsequence of A144856 and of A046528. [From _R. J. Mathar_, Sep 17 2009]
%F a(n)=A000668(n)*A000668(n+1). [From _R. J. Mathar_, Sep 17 2009]
%K nonn
%O 1,1
%A Boris Hostnik (megpplus(AT)siol.net), Sep 08 2009
%E Extended by _R. J. Mathar_, Sep 17 2009
%E Offset corrected by _N. J. A. Sloane_, Sep 20 2009