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!)
A280777 Denominators of coefficients in asymptotic expansion of C_n (number of connected chord diagrams, A000699). 6
1, 2, 8, 16, 128, 1280, 3072, 215040, 3440640, 2293760, 137625600, 201850880, 72666316800, 1889324236800, 52901078630400, 176336928768000, 135426761293824, 191854578499584000, 1593868805996544000, 787371190162292736000, 31494847606491709440000, 29395191099392262144000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
Michael Borinsky, Generating asymptotics for factorially divergent sequences, arXiv preprint arXiv:1603.01236 [math.CO], 2016.
EXAMPLE
Coefficients are 1, -5/2, -43/8, -579/16, -44477/128, -5326191/1280, -180306541/3072, ...
PROG
(PARI)
A000699_seq(N) = {
my(a = vector(N)); a[1] = 1;
for (n=2, N, a[n] = sum(k=1, n-1, (2*k-1)*a[k]*a[n-k])); a;
};
seq(N) = my(C = 'x*Ser(A000699_seq(N))); Vec(x*exp(1-(2*C+C^2)/(2*x))/C);
apply(denominator, seq(22)) \\ Gheorghe Coserea, Jan 22 2017
CROSSREFS
Sequence in context: A199043 A046161 A092978 * A013516 A259688 A101059
KEYWORD
nonn,frac
AUTHOR
N. J. A. Sloane, Jan 19 2017
EXTENSIONS
More terms from Gheorghe Coserea, Jan 22 2017
STATUS
approved

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 March 29 09:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)