0,3

G.f.: A(x) = B(x)/(1+x - x*B(x) ) where B(x) is the g.f. of A122446.

G.f. satisfies: A(x) = 1 + x*(1-2*x-2*x^2)*A(x) + x^2*(4+3*x)*A(x)^2. G.f.: A(x) = 2/(1-x+2*x^2+2*x^3 + (1+x)*sqrt(1-4*x-4*x^2+4*x^4)).

(PARI) {a(n)=polcoeff(2/(1-x+2*x^2+2*x^3+(1+x)*sqrt(1-4*x-4*x^2+4*x^4+x*O(x^n))), n)}

Cf. A122445, A122446, A122447, A122449, A122450, A122451, A122452.

Sequence in context: A126188 A081909 A126189 this_sequence A007582 A026854 A136576

Adjacent sequences: A122445 A122446 A122447 this_sequence A122449 A122450 A122451

nonn

Paul D. Hanna (pauldhanna(AT)juno.com), Sep 07 2006