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A143046 G.f. satisfies: A(x) = 1 + x*A(-x)^3. 4
1, 1, -3, -6, 35, 87, -588, -1578, 11511, 32223, -245883, -706824, 5556564, 16267508, -130617600, -387533058, 3161190783, 9474886287, -78241316361, -236394953670, 1971270824859, 5994591989967, -50388913722480, -154052058035736 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..23.

FORMULA

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

G.f. satisfies: [A(x)^4 + A(-x)^4]/2 = [A(x)^3 + A(-x)^3]/2.

EXAMPLE

G.f.: A(x) = 1 + x - 3*x^2 - 6*x^3 + 35*x^4 + 87*x^5 - 588*x^6 - 1578*x^7 +...

where

A(x)^3 = 1 + 3*x - 6*x^2 - 35*x^3 + 87*x^4 + 588*x^5 - 1578*x^6 - 11511*x^7 +...

A(x)^4 = 1 + 4*x - 6*x^2 - 56*x^3 + 87*x^4 + 1008*x^5 - 1578*x^6 - 20464*x^7 +...

Note that a bisction of A^4 equals a bisection of A^3.

PROG

(PARI) a(n)=local(A=x+x*O(x^n)); for(i=0, n, A=1+x*subst(A, x, -x)^3); polcoeff(A, n)

CROSSREFS

Cf. A143045, A143047, A143048, A143049, A213281.

Sequence in context: A068904 A309774 A244296 * A246069 A228279 A009197

Adjacent sequences:  A143043 A143044 A143045 * A143047 A143048 A143049

KEYWORD

sign

AUTHOR

Paul D. Hanna, Jul 19 2008

STATUS

approved

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Last modified May 18 15:25 EDT 2021. Contains 343995 sequences. (Running on oeis4.)