The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A091549 Second column (k=3) sequence of array A078740 ((3,2)-Stirling2) divided by 6. 1
1, 28, 960, 43200, 2520000, 186278400, 17069875200, 1902071808000, 253487646720000, 39833773056000000, 7291173820170240000, 1538106259064094720000, 370502654756909875200000 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,2
LINKS
FORMULA
a(n)= n!*(n+1)!*(-3 + (n+2)*(n+1)/2)/(3!)^2, n>=2.
E.g.f.: (hypergeom([2, 3], [], x) - 3*hypergeom([1, 2], [], x) + 2)/(3!)^2.
a(n)=product(j+2, j=0..n-1)* (-3*product(j+1, j=0..n-1) + product(j+3, j=0..n-1))/(3!)^2, n>=2. From eq.12 of the Blasiak et al. reference given in A078740 with r=3, s=2, k=3.
D-finite with recurrence a(n) +(-n^2-7*n-24)*a(n-1) +12*(n^2+4*n+6)*a(n-2) -36*n*(n+1)*a(n-3)=0. - R. J. Mathar, Jul 27 2022
MAPLE
A091549 := proc(n)
n!*(n+1)!*(-3 + (n+2)*(n+1)/2)/(3!)^2 ;
end proc:
seq(A091549(n), n=2..30) ; # R. J. Mathar, Jul 27 2022
CROSSREFS
Sequence in context: A239336 A203135 A097579 * A034904 A189995 A228689
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Feb 13 2004
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 June 18 07:40 EDT 2024. Contains 373469 sequences. (Running on oeis4.)