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

A192620

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

Terms

    a(0) =1a(1) =4a(2) =28a(3) =224a(4) =1948a(5) =17928a(6) =171776a(7) =1695872a(8) =17133436a(9) =176297668a(10) =1841222776a(11) =19467629120a(12) =207978652416

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