

A112125


G.f. A(x) satisfies A(A(A(..(A(x))..))) = B(x) (12th selfCOMPOSE of A) such that the coefficients of B(x) consist only of numbers {1,2,3,..,12}, with B(0) = 0.


3



1, 1, 10, 160, 3061, 63775, 1381434, 30233546, 654989371, 13821523157, 280493565375, 5432981693533, 100769609590332, 1833421110751790, 34286913831217395, 678578947805323394, 13377225136748683778, 221000164094797572734, 2119677884300620846621
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OFFSET

1,3


LINKS

Table of n, a(n) for n=1..19.


EXAMPLE

A(x) = x + x^2  10*x^3 + 160*x^4  3061*x^5 + 63775*x^6 +...
where A(A(A(A(A(A(A(A(A(A(A(A(x)))))))))))) =
x + 12*x^2 + 12*x^3 + 6*x^4 + 8*x^5 + 8*x^6 + 12*x^7 + 2*x^8 +...
is the g.f. of A112124.


PROG

(PARI) {a(n, m=12)=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, m1, G=subst(F, x, G)); F=F((polcoeff(G, k)1)\m)*x^k); return(polcoeff(F, n, x)))}


CROSSREFS

Cf. A112124, A112104A112123, A112126, A112127.
Sequence in context: A284110 A180881 A106261 * A090374 A034724 A234283
Adjacent sequences: A112122 A112123 A112124 * A112126 A112127 A112128


KEYWORD

sign


AUTHOR

Paul D. Hanna, Aug 27 2005


STATUS

approved



