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%I #14 Jul 27 2016 10:21:44
%S 0,2,1,2,2,3,3,5,3,6
%N Number of odd prime factors (with multiplicity) of generalized Fermat number 7^(2^n) + 1.
%F a(n) = A001222(A078304(n)) for n > 0. - _Felix Fröhlich_, Jul 25 2016
%e b(n) = (7^(2^n) + 1)/2.
%e Complete Factorizations
%e b(0) = 2*2
%e b(1) = 5*5
%e b(2) = 1201
%e b(3) = 17*169553
%e b(4) = 353*47072139617
%e b(5) = 7699649*134818753*531968664833
%e b(6) = 35969*1110623386241*15266848196793556098085000332888634369
%e b(7) = 257*769*197231873*6856531741041792239054980342217258517995521*P52
%e b(8) = 28667393*126575155274810369*P192
%e b(9) = 13313*943558259713*
%e 275102002206713516320479233*1338330888777063359811677099009*
%e 656929861401793262700329631944023570433*P321
%Y Cf. A078304, A273948.
%K nonn,hard,more
%O 0,2
%A _Arkadiusz Wesolowski_, Jul 25 2016
%E a(9) was found by Nestor de Araújo Melo and Geoffrey Reynolds (2008)
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