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2^(2^(2^x)+1)-1 = M(F(x)) == Mersenne(Fermat(x))
0

%I #10 Jul 20 2024 15:09:12

%S 7,31,131071,

%T 231584178474632390847141970017375815706539969331281128078915168015826259279871

%N 2^(2^(2^x)+1)-1 = M(F(x)) == Mersenne(Fermat(x))

%C Mersenne-Fermat numbers.

%F a(n) = A070969(2^n)-2. - _R. J. Mathar_, Apr 22 2007

%e M(F(0))=7

%e M(F(1))=31

%e M(F(2))=131071

%e M(F(3))=231584178474632390847141970017375815706539969331281128078915168015826259279871

%o (PARI) for(x=0,3,print(2^(2^(2^x)+1)-1))

%K nonn

%O 0,1

%A _Jorge Coveiro_, Dec 24 2004