OFFSET
1,6
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (17, -136, 680, -2380, 6188, -12376, 19448, -24310, 24310, -19448, 12376, -6188, 2380, -680, 136, -17, 1).
FORMULA
a(n) = 1/40320*n^2 * (n^14 -252*n^12 +27874*n^10 -1759800*n^8 +68745649*n^6 -1669136028*n^4 +23447322156*n^2 -147931524720), n>=9.
G.f.: x^6*(17728x^19 - 301964x^18 + 2573500x^17 - 13833040x^16 + 51521058x^15 - 143708688x^14 + 325486412x^13 - 629393865x^12 + 996601251x^11 - 1090603627x^10 + 426710617x^9 + 807953488x^8 - 1328885640x^7 + 262625618x^6 + 1106513030x^5 - 875387697x^4 - 386005021x^3 - 30462955x^2 - 338119x - 486)/(x-1)^17.
MATHEMATICA
CoefficientList[Series[x^5 (17728 x^19 - 301964 x^18 + 2573500 x^17 - 13833040 x^16 + 51521058 x^15 - 143708688 x^14 + 325486412 x^13 - 629393865 x^12 + 996601251 x^11 - 1090603627 x^10 + 426710617 x^9 + 807953488 x^8 - 1328885640 x^7 + 262625618 x^6 + 1106513030 x^5 - 875387697 x^4 - 386005021 x^3 - 30462955 x^2 - 338119 x - 486) / (x - 1)^17, {x, 0, 50}], x] (* Vincenzo Librandi, Jun 01 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Jan 07 2011
STATUS
approved