OFFSET
1,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = n*(n - 3)(n^4 + 3*n^3 - 18*n^2 - 18*n + 164)/6, n>=6.
G.f.: -2*x^3*(15*x^9-141*x^8+564*x^7-1276*x^6+1812*x^5-1652*x^4+908*x^3-272*x^2+99*x+3)/(x-1)^7. - Vaclav Kotesovec, Mar 25 2010
MATHEMATICA
CoefficientList[Series[- 2 x^2 (15 x^9 - 141 x^8 + 564 x^7 - 1276 x^6 + 1812 x^5 - 1652 x^4 + 908 x^3 - 272 x^2 + 99 x + 3) / (x - 1)^7, {x, 0, 40}], x] (* Vincenzo Librandi, May 29 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vaclav Kotesovec, Feb 06 2010
EXTENSIONS
More terms from Vincenzo Librandi, May 29 2013
STATUS
approved