a(n) = 2^(n*(n-1))*(2^n + 1)*Product_{i=1..n-1} (4^i - 1).

A144545

a(n) = 2^(n*(n-1))*(2^n + 1)*Product_{i=1..n-1} (4^i - 1).

Terms

    a(0) =2a(1) =3a(2) =60a(3) =25920a(4) =197406720

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