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!)
A144690 Limit of the coefficient of x^(2^m+n) in B(x)^(n+1) as m grows, where B(x) = Sum_{k>=0} x^(2^k). 5
1, 2, 6, 16, 130, 636, 5712, 34336, 811458, 7151380, 113034746, 1049982792, 25276020640, 293841338896, 5712436923000, 68827002466176, 3739997267623490, 60752008945662372, 1718332635327516238, 26832922324005759560, 1099199814287516279394 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The g.f. of A144691(n) = a(n)/(n+1) appears to have an interesting functional interpretation.

For a fixed n, the sequence of [x^(2^m+n)] B(x)^(n+1), m=0,1,2,... seems to stabilize at m = n + A023416(n). [From Max Alekseyev, Dec 19 2011]

LINKS

Max Alekseyev, Table of n, a(n) for n = 0..27

FORMULA

a(n) = (n+1)*A144691(n).

PROG

(PARI) { a(n) = local(m=n+log(n+.5)\log(2), B=sum(k=0, m, x^(2^k))); if(n<0, 0, polcoeff((B+O(x^(2^m+n+1)))^(n+1), 2^m+n)) }

CROSSREFS

Cf. A007178, A144691, A144692, A135068, A135069, A135070, A135071.

Sequence in context: A147923 A341838 A325790 * A317351 A296108 A118305

Adjacent sequences:  A144687 A144688 A144689 * A144691 A144692 A144693

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Oct 10 2008

EXTENSIONS

a(14), a(15) corrected and a(16)-a(23) added by Max Alekseyev, May 03 2011

a(24)-a(27) in b-file from Max Alekseyev, Dec 19 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 September 24 09:10 EDT 2021. Contains 347630 sequences. (Running on oeis4.)