OFFSET
0,3
EXAMPLE
E.g.f.: A(x) = 1 + x + 3*x^2/2! + 16*x^3/3! + 197*x^4/4! + 5556*x^5/5! +...
where
A(x) = 1 + x*A(x) + x^2*A(4*x)^(1/2)/2! + x^3*A(9*x)^(1/3)/3! + x^4*A(16*x)^(1/4)/4! +...
Related expansions begin:
A(4*x)^(1/2) = 1 + 2*x + 20*x^2/2! + 392*x^3/3! + 20880*x^4/4! +...
A(9*x)^(1/3) = 1 + 3*x + 63*x^2/2! + 2700*x^3/3! + 335421*x^4/4! +...
A(16*x)^(1/4) = 1 + 4*x + 144*x^2/2! + 10816*x^3/3! + 2437376*x^4/4! +...
A(25*x)^(1/5) = 1 + 5*x + 275*x^2/2! + 32000*x^3/3! + 11413125*x^4/4! +...
A(36*x)^(1/6) = 1 + 6*x + 468*x^2/2! + 77976*x^3/3! + 40405392*x^4/4! +...
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=1+sum(m=1, n, x^m/m!*subst(A, x, m^2*x+x*O(x^n))^(1/m))); n!*polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 03 2011
STATUS
approved