The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A027771 a(n) = (n+1)*binomial(n+1,11). 2
 11, 144, 1014, 5096, 20475, 69888, 210392, 572832, 1436058, 3359200, 7407036, 15519504, 31097794, 59907456, 111435000, 200880160, 352023165, 601277040, 1003321410, 1638819000, 2624841765, 4128783360, 6386711760, 9727323840, 14602906500, 21628990656 (list; graph; refs; listen; history; text; internal format)
 OFFSET 10,1 COMMENTS Number of 13-subsequences of [ 1, n ] with just 1 contiguous pair. 1214673*a(n) is the number of permutations of (n+1) symbols that 11-commute with an (n+1)-cycle (see A233440 for definition), where 1214673 = A000757(11). - Luis Manuel Rivera MartÃ­nez, Feb 07 2014 LINKS T. D. Noe, Table of n, a(n) for n = 10..1000 Luis Manuel Rivera, Integer sequences and k-commuting permutations, arXiv preprint arXiv:1406.3081 [math.CO], 2014-2015. Index entries for linear recurrences with constant coefficients, signature (13,-78,286,-715,1287,-1716,1716,-1287,715,-286,78,-13,1). FORMULA G.f.: (11+x)*x^10/(1-x)^13. From Amiram Eldar, Jan 30 2022: (Start) Sum_{n>=10} 1/a(n) = 11*Pi^2/6 - 57138257/3175200. Sum_{n>=10} (-1)^n/a(n) = 11*Pi^2/12 + 822272*log(2)/315 - 5773608863/3175200. (End) MATHEMATICA Table[(n+1)*Binomial[n+1, 11], {n, 10, 35}] (* Amiram Eldar, Jan 30 2022 *) CROSSREFS Cf. A000757, A233440. Sequence in context: A015687 A051583 A225799 * A098310 A293610 A061613 Adjacent sequences:  A027768 A027769 A027770 * A027772 A027773 A027774 KEYWORD nonn,easy AUTHOR Thi Ngoc Dinh (via R. K. Guy) 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.

Last modified May 21 05:07 EDT 2022. Contains 353887 sequences. (Running on oeis4.)