OFFSET
0,3
EXAMPLE
G.f.: A(x)=1+x/B(x)^3, B(x)=1+x/C(x)^6, C(x)=1+x/D(x)^9, D(x)=1+x/E(x)^12, ...
where A(x),B(x),C(x),... are the g.f. of the sequences given below.
A=[1,1,-3,24,-307,5367,-118836,3185098,-100249284,...];
B=[1,1,-6,75,-1352,31167,-867294,28172631,-1044977994,...];
C=[1,1,-9,153,-3567,102591,-3461832,133195605,-5737614804,...];
D=[1,1,-12,258,-7384,254955,-10139508,452535442,-22298633472,...];
E=[1,1,-15,390,-13235,533700,-24472908,1245207030,-69239330640,...];
F=[1,1,-18,549,-21552,994392,-51685074,2955896076,-183324843810,...]; ...
PROG
(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(j=0, n-1, A=1+x*A^(-3*(n-j))); polcoeff(A, n)}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Mar 06 2008
STATUS
approved