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!)
A179580 Number of permutations of 1..n+5 with the number moved left exceeding the number moved right by n or more 1
219, 534, 1236, 2774, 6109, 13290, 28670, 61466, 131135, 278638, 589992, 1245422, 2621761, 5505442, 11534866, 24117906, 50332451, 104858566, 218104956, 452986182, 939525669, 1946158874, 4026533926, 8321501514, 17179871879 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Recurrence would also extend to an a(0) if the definition were made to exclude the identity permutation

LINKS

R. H. Hardin, Table of n, a(n) for n=1..99

FORMULA

Empirical: a(n)=8*a(n-1)-26*a(n-2)+44*a(n-3)-41*a(n-4)+20*a(n-5)-4*a(n-6) ; G.f.: -x*(-219+1218*x-2658*x^2+2866*x^3-1536*x^4+328*x^5) / ( (2*x-1)^2*(x-1)^4 ).

Empirical: a(n) = (n+5)*(n^2-2*n-36)/6 +(n+7)*2^(n+4). - R. J. Mathar, May 26 2016

CROSSREFS

Sequence in context: A025404 A192086 A256815 * A043435 A166836 A200827

Adjacent sequences:  A179577 A179578 A179579 * A179581 A179582 A179583

KEYWORD

nonn

AUTHOR

R. H. Hardin, g.f. from R. J. Mathar in the Sequence Fans Mailing List, Jul 19 2010

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 April 5 03:58 EDT 2020. Contains 333238 sequences. (Running on oeis4.)