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A107701 Self-COMPOSE of A107700; thus g.f. A(x) = G(G(x)) = x + 2*G(x)^2, where G(x) is the g.f. of A107700. 2
1, 2, 4, 6, 4, -6, -8, 44, 52, -520, -580, 8628, 9312, -188326, -199136, 5210560, 5435860, -178308938, -184306176, 7409693156, 7608810060, -368330924160, -376418726640, 21620184591972, 22015468707328, -1481473941622200, -1504385498284500, 117304374434860032 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..28.

FORMULA

G.f. satisfies: A(-A(-x)) = x.

PROG

(PARI) {a(n)=local(A, B, F); A=x+x^2+x*O(x^n); if(n<1, 0, for(i=0, n, F=x+2*A^2; B=serreverse(A); A=(A+subst(B, x, F))/2); polcoeff(x+2*A^2, n, x))}

CROSSREFS

Cf. A107699, A107700.

Sequence in context: A098793 A083220 A085896 * A293812 A011176 A154542

Adjacent sequences:  A107698 A107699 A107700 * A107702 A107703 A107704

KEYWORD

sign

AUTHOR

Paul D. Hanna, May 21 2005

STATUS

approved

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Last modified February 27 12:22 EST 2020. Contains 332306 sequences. (Running on oeis4.)