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%I #11 Sep 27 2024 05:41:39
%S 6,42,930,16002,67084290,17179475970,274876334082,4611686011984936962,
%T 5316911983139663484697699213480296450,
%U 383123885216472214589586754930667236976614368197214210
%N M*(M-1), where M is Mersenne prime A000668(n).
%H Omar E. Pol, <a href="http://www.polprimos.com">Determinacion geometrica de los numeros primos y perfectos</a>.
%F a(n) = A000668(n)*(A000668(n)-1).
%Y Cf. A000668, A036689, A139115, A139116, A139224, A139225, A139226, A139256.
%K nonn,changed
%O 1,1
%A _Omar E. Pol_, May 10 2008
%E More terms from _R. J. Mathar_, Jun 24 2009