This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A275381 #17 Jul 27 2016 10:22:32
%S A275381 1,1,2,2,5,4,3,4,5
%N A275381 Number of prime factors (with multiplicity) of generalized Fermat number 10^(2^n) + 1.
%F A275381 a(n) = A001222(A080176(n)). - _Felix Fröhlich_, Jul 25 2016
%e A275381 b(n) = 10^(2^n) + 1.
%e A275381 Complete Factorizations
%e A275381 b(0) = 11
%e A275381 b(1) = 101
%e A275381 b(2) = 73*137
%e A275381 b(3) = 17*5882353
%e A275381 b(4) = 353*449*641*1409*69857
%e A275381 b(5) = 19841*976193*6187457*834427406578561
%e A275381 b(6) = 1265011073*
%e A275381 15343168188889137818369*515217525265213267447869906815873
%e A275381 b(7) = 257*15361*453377*P116
%e A275381 b(8) = 10753*8253953*9524994049*73171503617*P225
%t A275381 Table[PrimeOmega[10^(2^n) + 1], {n, 0, 6}] (* _Michael De Vlieger_, Jul 26 2016 *)
%o A275381 (PARI) a(n) = bigomega(factor(10^(2^n)+1))
%Y A275381 Cf. A072982, A080176.
%K A275381 nonn,hard,more
%O A275381 0,3
%A A275381 _Arkadiusz Wesolowski_, Jul 25 2016