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A112113
G.f. A(x) satisfies A(A(A(..(A(x))..))) = B(x) (6th self-COMPOSE of A) such that the coefficients of B(x) consist only of numbers {1,2,3,..,6}, with B(0) = 0.
3
1, 1, -4, 28, -236, 2159, -20309, 189387, -1696165, 14092143, -103605487, 621674576, -2503235595, 1311059747, 58857366823, -625935119621, 20416246154579, -595556154741631, 9331660766550500, -50486760747953952, -816026626910008666
OFFSET
1,3
EXAMPLE
A(x) = x + x^2 - 4*x^3 + 28*x^4 - 236*x^5 + 2159*x^6 +...
where A(A(A(A(A(A(x)))))) =
x + 6*x^2 + 6*x^3 + 3*x^4 + 4*x^5 + 4*x^6 + 6*x^7 + 2*x^8 +...
is the g.f. of A112112.
PROG
(PARI) {a(n, m=6)=local(F=x+x^2+x*O(x^n), G); if(n<1, 0, for(k=3, n, G=F+x*O(x^k); for(i=1, m-1, G=subst(F, x, G)); F=F-((polcoeff(G, k)-1)\m)*x^k); return(polcoeff(F, n, x)))}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Aug 27 2005
STATUS
approved