login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A138212 G.f.: A(x) = 1 + x*(1 + x*(1 + x*(...(1 + x*(...)^(2n))...)^6)^4)^2. 9

%I #4 Oct 02 2020 15:54:04

%S 1,1,2,9,68,732,10250,176654,3613044,85476720,2295275372,68949496421,

%T 2290588299708,83374406924240,3299390271801838,141034101443780374,

%U 6475752407825487220,317866884692663325892,16609896989101220207880

%N G.f.: A(x) = 1 + x*(1 + x*(1 + x*(...(1 + x*(...)^(2n))...)^6)^4)^2.

%H Vaclav Kotesovec, <a href="/A138212/b138212.txt">Table of n, a(n) for n = 0..340</a>

%e G.f.: A(x)=1+x*B(x)^2, B(x)=1+x*C(x)^4, C(x)=1+x*D(x)^6, D(x)=1+x*E(x)^8, ...

%e where A(x),B(x),C(x),... are the g.f. of the sequences given below.

%e A=[1,1,2,9,68,732,10250,176654,3613044,85476720,...];

%e B=[1,1,4,30,328,4677,81888,1696086,40520620,1096342026,...];

%e C=[1,1,6,63,908,16311,347466,8519957,235763712,7259384208,...];

%e D=[1,1,8,108,1936,42110,1062416,30283824,958845640,...];

%e E=[1,1,10,165,3540,90550,2646522,86251140,3086189660,...];

%e F=[1,1,12,234,5848,172107,5725392,210342902,8410505748,...]; ...

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

%Y Cf. A095793, A138211, A138213, A138214, A138215, A138216.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Mar 06 2008

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 28 01:15 EDT 2024. Contains 375477 sequences. (Running on oeis4.)