login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A192635 G.f. satisfies: A(x) = exp( Sum_{n>=1} x^n*A(x^n/(1-x^n))/n ). 1
1, 1, 2, 5, 16, 57, 234, 1045, 5103, 26791, 150492, 898497, 5676600, 37797128, 264348852, 1936248546, 14814452947, 118126621277, 979597024690, 8432780717866, 75227768490441, 694375113431739, 6622156995890563, 65166502098671053 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Compare to g.f. G(x) of A000081 (number of rooted trees with n nodes), which satisfies: G(x) = exp( Sum_{n>=1} x^n*G(x^n)/n ).

LINKS

Table of n, a(n) for n=0..23.

EXAMPLE

G.f.: A(x) =  1 + x + 2*x^2 + 5*x^3 + 16*x^4 + 57*x^5 + 234*x^6 +...

The g.f. A(x) satisfies:

log(A(x)) = x*A(x/(1-x)) + x^2*A(x^2/(1-x^2))/2 + x^3*A(x^3/(1-x^3))/3 +...

PROG

(PARI) {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, x^m*subst(A, x, x^m/(1-x^m+x*O(x^n)))/m))); polcoeff(A, n)}

CROSSREFS

Cf. A191412, A192634, A000081.

Sequence in context: A188314 A114296 A121689 * A009225 A157612 A184943

Adjacent sequences:  A192632 A192633 A192634 * A192636 A192637 A192638

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jul 06 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 14 16:29 EDT 2019. Contains 328022 sequences. (Running on oeis4.)