a(0) = a(1) = 0; for n >= 2, a(n)*2^(n+2) + 1 is the smallest prime factor of the n-th Fermat number F(n) = 2^(2^n) + 1.

A007117

a(0) = a(1) = 0; for n >= 2, a(n)*2^(n+2) + 1 is the smallest prime factor of the n-th Fermat number F(n) = 2^(2^n) + 1.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =8a(4) =1024a(5) =5a(6) =1071a(9) =1184a(10) =11131a(11) =39a(12) =7a(13) =82731770a(15) =9264a(16) =3150a(17) =59251857a(18) =13a(19) =33629

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