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 A330829 #16 Jan 12 2020 13:43:16
%S A330829 72,800,147968,8657174528,36894614055915880448
%N A330829 Numbers of the form 2^(2*(2^n)+1)*F_n^2, where F_n is a Fermat prime A019434.
%C A330829 Also numbers with power-spectral basis {(F_n-2)^2*F_n^2,(F_n^2-1)^2}.
%C A330829 The first element of the power-spectral basis of a(n) is A330830, and the second element is A330831. The first factor of a(n) is A000051(n) and the second factor is A330828.
%F A330829 a(n) = 2^(2*(2^n)+1)*(2^(2^n)+1)^2.
%e A330829 a(0) = 2^(2+1)*(2+1)^2 = 72, and the spectral basis is {(3-2)^2*3^2, (3^2-1)^2} = {9,64}, consisting of powers.
%p A330829 F := proc(n) return 2^(2^n)+1 end;
%p A330829 G := proc(n) return 2^(2*(2^n)+1) end;
%p A330829 a := proc(n) if isprime(F(n)) then return G(n)*F(n)^2 fi; end;
%p A330829 [seq(a(n),n=0..4)];
%Y A330829 Cf. A000215, A001146, A019434, A000051, A330828, A330830, A330831.
%K A330829 nonn
%O A330829 0,1
%A A330829 _Walter Kehowski_, Jan 06 2020