%I #13 Jun 17 2017 02:59:45
%S -2,-2,6,28,70,138,238,376,558,790,1078,1428,1846,2338,2910,3568,4318,
%T 5166,6118,7180,8358,9658,11086,12648,14350,16198,18198,20356,22678,
%U 25170,27838,30688,33726,36958,40390,44028,47878
%N n*(n^2-2*n-1)
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F a(n) = -2*A110427(n). G.f. 2*x*(-1+3*x+x^2) / (x-1)^4 . - _R. J. Mathar_, Jul 18 2012
%o (PARI) a(n) = n*(n^2 - 2*n - 1) \\ _Michel Marcus_, Jul 15 2013
%K sign,easy
%O 1,1
%A _Marco Piazzalunga_, Jul 18 2012