A330829 Numbers of the form 2^(2*(2^n)+1)*F_n^2, where F_n is a Fermat prime A019434.
72, 800, 147968, 8657174528, 36894614055915880448
Offset: 0
Keywords
Examples
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.
Programs
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Maple
F := proc(n) return 2^(2^n)+1 end; G := proc(n) return 2^(2*(2^n)+1) end; a := proc(n) if isprime(F(n)) then return G(n)*F(n)^2 fi; end; [seq(a(n),n=0..4)];
Formula
a(n) = 2^(2*(2^n)+1)*(2^(2^n)+1)^2.
Comments