login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A112805 Expansion of solution of functional equation. 0

%I

%S 1,1,1,1,1,2,5,11,21,37,66,127,261,545,1119,2255,4529,9202,18989,

%T 39566,82614,172272,359159,750699,1575649,3319942,7012833,14834345,

%U 31414423,66619692,141526459,301202699,642055773,1370429491,2928418794

%N Expansion of solution of functional equation.

%F G.f. A(x)=y satisfies y=x+(xy)/(1-(xy)^2).

%F Series reversion of g.f. A(x) is -A(-x).

%o (PARI) {a(n)=local(A); if(n<1, 0, A=x+O(x^2); for(k=1,n, A=x+subst(x/(1-x^2),x,x*A)); polcoeff(A,n))}

%K nonn

%O 1,6

%A _Michael Somos_, Sep 20 2005

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 May 9 12:26 EDT 2021. Contains 343740 sequences. (Running on oeis4.)