|
%I #2 Mar 30 2012 18:37:10
%S 1,1,6,75,1338,29610,762228,22038705,700625130,24149689410,
%T 893830956468,35275412216850,1476645034008396,65297205101393700,
%U 3040249608438530040,148645372286538383895,7614315445406159805786,407837347813468711863270
%N G.f. satisfies: 2*A(x) = 5*x - x^2 - 3*Series_Reversion( A(x) ).
%F a(n) = (3/2)*(-1)^n*A139087(n) for n>2 with a(1)=a(2)=1.
%e G.f.: A(x) = x + x^2 + 6*x^3 + 75*x^4 + 1338*x^5 + 29610*x^6 +...
%e Series_Reversion(A(x)) = x - x^2 - 4*x^3 - 50*x^4 - 892*x^5 - ...
%e which equals -G(-x) where G(x) = g.f. of A139087.
%o (PARI) {a(n)=local(A=x+x^2);if(n<1,0, for(i=3,n+1,A=A+3*polcoeff(serreverse(A+x*O(x^i)),i)*x^i);polcoeff(A,n))}
%Y Cf. A139087.
%K nonn
%O 1,3
%A _Paul D. Hanna_, Apr 08 2008
|
