E.g.f.: Sum_{n>=0} d^n/dx^n (x + x^2)^(2*n) / (2*n)!.

A215125

E.g.f.: Sum_{n>=0} d^n/dx^n (x + x^2)^(2*n) / (2*n)!.

Terms

    a(0) =1a(1) =1a(2) =7a(3) =33a(4) =223a(5) =1753a(6) =14391a(7) =137137a(8) =1382383a(9) =14981673a(10) =174494983a(11) =2135204161a(12) =27643067007a(13) =375548195833

External references