G.f.: A(x) = Sum_{n>=0} x^n * Product_{k=1..n} (2^(2*k-1) - 1) / (1 + 2^(2*k-1)*x).

A214691

G.f.: A(x) = Sum_{n>=0} x^n * Product_{k=1..n} (2^(2*k-1) - 1) / (1 + 2^(2*k-1)*x).

Terms

    a(0) =1a(1) =1a(2) =5a(3) =151a(4) =19025a(5) =9702751a(6) =19851828545

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