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!)
A050149 a(n) = T(n,n-3), array T as in A050143. 1
1, 15, 80, 432, 2352, 12896, 71136, 394400, 2196128, 12273648, 68811184, 386838480, 2179890000, 12309739968, 69641542848, 394643939904, 2239678552640, 12727572969680, 72415319422992, 412470467298032 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,2

LINKS

Table of n, a(n) for n=3..22.

FORMULA

a(n) = Sum_{s=1..n} binomial(n,s)*binomial(s+n-5,n-4) = n*hypergeom([-n + 1, n-3], [2], -1) for n >= 4 and a(1) = 1. - Petros Hadjicostas, Feb 14 2021

CROSSREFS

Sequence in context: A059377 A123865 A024002 * A055815 A338414 A244855

Adjacent sequences:  A050146 A050147 A050148 * A050150 A050151 A050152

KEYWORD

nonn

AUTHOR

Clark Kimberling

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 March 2 06:30 EST 2021. Contains 341743 sequences. (Running on oeis4.)