OFFSET
1,3
FORMULA
Logarithmic derivative of A226907.
EXAMPLE
G.f.: L(x) = x + x^2/2 + 4*x^3/3 + 9*x^4/4 + 26*x^5/5 + 64*x^6/6 +...
where G(x) = exp(L(x)) satisfies
G(x) = 1 + x*exp( x*G(x) + x^2*G(x^2)/2 + 4*x^3*G(x^3)/3 + 9*x^4*G(x^4)/4 + 26*x^5*G(x^5)/5 + 64*x^6*G(x^6)/6 +...+ a(n)*x^n*G(x^n)/n +... )
and equals the g.f. of A226907:
G(x) = 1 + x + x^2 + 2*x^3 + 4*x^4 + 9*x^5 + 20*x^6 + 48*x^7 + 113*x^8 + 276*x^9 + 677*x^10 +...+ A226907(n)*x^n +...
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=1+x*exp(sum(m=1, n, polcoeff(log(A+x*O(x^m)), m)*subst(A, x, x^m)*x^m)+x*O(x^n))); n*polcoeff(log(A), n)}
for(n=1, 25, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jun 21 2013
STATUS
approved