A302097 Number of odd prime factors (with multiplicity) of generalized Fermat number 13^(2^n) + 1.
1, 2, 1, 1, 3, 4, 4, 3
Offset: 0
Examples
b(n) = (13^(2^n) + 1)/2. Complete factorizations: b(0) = 7 b(1) = 5*17 b(2) = 14281 b(3) = 407865361 b(4) = 2657*441281*283763713 b(5) = 193*1601*10433*68675120456139881482562689 b(6) = 257*3230593*36713826768408543617*3215877717636198473712500018174097551256193 b(7) = 96769*2940673*P131
Programs
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PARI
a(n) = bigomega((13^(2^n)+1)/2)
Comments