G.f. satisfies Sum_{n>=0} x^n * abs(1/A(x)^n) = C(x), where C(x) = 1 + x*C(x)^2 and abs(F(x)) equals the series expansion formed by the unsigned coefficients in F(x).

A382122

G.f. satisfies Sum_{n>=0} x^n * abs(1/A(x)^n) = C(x), where C(x) = 1 + x*C(x)^2 and abs(F(x)) equals the series expansion formed by the unsigned coefficients in F(x).

Terms

    a(0) =1a(1) =1a(2) =3a(3) =12a(4) =49a(5) =202a(6) =838a(7) =3486a(8) =14575a(9) =60820a(10) =254406a(11) =1061438a(12) =4444802a(13) =18602018a(14) =78066384a(15) =326985608a(16) =1365996909a(17) =5697914836a(18) =23752394338a(19) =99027785702a(20) =413203462516

External references