G.f.: Sum_{n>=0} (3*n+1)^n * x^n / (1 + (3*n+1)*x)^n.

A187738

G.f.: Sum_{n>=0} (3*n+1)^n * x^n / (1 + (3*n+1)*x)^n.

Terms

    a(0) =1a(1) =4a(2) =33a(3) =378a(4) =5508a(5) =97200a(6) =2012040a(7) =47764080a(8) =1278607680a(9) =38093690880

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