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!)
A159736 Number of permutations of 6 indistinguishable copies of 1..n arranged in a circle with exactly 1 local maximum. 8
12, 126, 1176, 10290, 86436, 705894, 5647152, 44471322, 345888060, 2663338062, 20338217928, 154231485954, 1162668124884, 8720010936630, 65109414993504, 484251274014186, 3589156501516908, 26519878594541598, 195409631749253880 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,1
LINKS
FORMULA
a(n) = (copies*n)*(copies+1)^(n-2).
From G. C. Greubel, Jun 01 2018: (Start)
a(n) = 6*n*7^(n-2).
a(n) = 14*a(n-1) - 49*a(n-2).
G.f.: x^2*(12-42*x)/(1-14*x+49*x^2).
E.g.f.: 6*x*exp(7*x)/7. (End)
From Amiram Eldar, May 16 2022: (Start)
Sum_{n>=2} 1/a(n) = (49/6)*log(7/6) - 7/6.
Sum_{n>=2} (-1)^n/a(n) = 7/6 - (49/6)*log(8/7). (End)
MATHEMATICA
LinearRecurrence[{14, -49}, {12, 126}, 30] (* or *) Table[6*n*7^(n-2), {n, 2, 30}] (* G. C. Greubel, Jun 01 2018 *)
PROG
(PARI) for(n=2, 30, print1(6*n*7^(n-2), ", ")) \\ G. C. Greubel, Jun 01 2018
(Magma) I:=[12, 126]; [n le 2 select I[n] else 14*Self(n-1) - 49*Self(n-2): n in [1..30]]; // G. C. Greubel, Jun 01 2018
CROSSREFS
Sequence in context: A015792 A343769 A348463 * A004991 A228008 A101602
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 20 2009
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 15 22:50 EDT 2024. Contains 373412 sequences. (Running on oeis4.)