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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A336228 a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^2 * (n-k) * a(k). 1
1, 1, 6, 75, 1684, 59005, 2977566, 204512875, 18346977608, 2083115635065, 291996210173410, 49525220811387871, 9996609976117991436, 2368117724291275331869, 650613686811158069472942, 205196311013650099853516115, 73633144885479474283911225616 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..16.

FORMULA

a(n) = (n!)^2 * [x^n] 1 / (1 - sqrt(x) * BesselI(1,2*sqrt(x))).

MATHEMATICA

a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^2 (n - k) a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 16}]

nmax = 16; CoefficientList[Series[1/(1 - Sqrt[x] BesselI[1, 2 Sqrt[x]]), {x, 0, nmax}], x] Range[0, nmax]!^2

CROSSREFS

Cf. A006153, A102221.

Sequence in context: A126462 A081066 A185289 * A326011 A263228 A229571

Adjacent sequences:  A336225 A336226 A336227 * A336229 A336230 A336231

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Jul 12 2020

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 December 3 17:23 EST 2021. Contains 349467 sequences. (Running on oeis4.)