A112119 G.f. A(x) satisfies A(A(A(..(A(x))..))) = B(x) (9th self-COMPOSE of A) such that the coefficients of B(x) consist only of numbers {1,2,3,..,9}, with B(0) = 0.

1, 1, -7, 81, -1122, 16906, -264109, 4150081, -64119406, 955386299, -13491950523, 178108552187, -2193288809125, 25965294143459, -320197330438145, 4331428366450929, -54509980572007649, 309687851858995853, 8841175049606909354, -260481122023484957344, 727627679068983588258

Offset: 1

Author

Paul D. Hanna, Aug 27 2005

Keywords

• sign

Examples

			A(x) = x + x^2 - 7*x^3 + 81*x^4 - 1122*x^5 + 16906*x^6 +...
where A(A(A(A(A(A(A(A(A(x))))))))) =
x + 9*x^2 + 9*x^3 + 9*x^4 + 6*x^5 + 6*x^6 + 3*x^7 +...
is the g.f. of A112118.
		

Crossrefs

Cf. A112118, A112104-A112117, A112120-A112127.

Programs

PARI

{a(n,m=9)=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)))}