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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A014309 a(n) = (n+2)*(n+1)*(n^2 + 7*n - 12)/24. 1
 -1, 3, 15, 40, 84, 154, 258, 405, 605, 869, 1209, 1638, 2170, 2820, 3604, 4539, 5643, 6935, 8435, 10164, 12144, 14398, 16950, 19825, 23049, 26649, 30653, 35090, 39990, 45384, 51304, 57783, 64855, 72555 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..725 Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1). FORMULA G.f.: x*(1 + x^4 - 5*x^3 + 10*x^2 - 8*x)/(x-1)^5. - Maksym Voznyy (voznyy(AT)mail.ru), Aug 10 2009 E.g.f.: (24 - (24 - 48*x^2 - 16*x^3 - x^4)*exp(x))/24. - G. C. Greubel, Jun 12 2019 a(n) = binomial(n+2,4) + 2*binomial(n+2,3) - binomial(n+2,2). - Étienne Tétreault, Sep 02 2020 MATHEMATICA Table[(n+2)(n+1)(n^2+7n-12)/24, {n, 40}] (* Harvey P. Dale, Feb 20 2011 *) PROG (Magma) [(n+2)*(n+1)*(n^2+7*n-12)/24: n in [1..40]]; // Vincenzo Librandi, Apr 25 2011 (PARI) {a(n) = (n+2)*(n+1)*(n^2+7*n-12)/24}; \\ G. C. Greubel, Jun 12 2019 (Sage) [(n+2)*(n+1)*(n^2+7*n-12)/24 for n in (1..40)] # G. C. Greubel, Jun 12 2019 (GAP) List([1..40], n-> (n+2)*(n+1)*(n^2+7*n-12)/24) # G. C. Greubel, Jun 12 2019 CROSSREFS Sequence in context: A146853 A183476 A297621 * A298049 A298884 A298655 Adjacent sequences: A014306 A014307 A014308 * A014310 A014311 A014312 KEYWORD sign,easy AUTHOR 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 March 29 11:36 EDT 2023. Contains 361599 sequences. (Running on oeis4.)