A248160 - OEIS

%I #18 Jan 14 2023 12:41:21

%S 1,-5,13,-25,40,-56,70,-78,75,-55,11,65,-182,350,-580,884,-1275,1767,

%T -2375,3115,-4004,5060,-6302,7750,-9425,11349,-13545,16037,-18850,

%U 22010,-25544,29480,-33847,38675,-43995,49839,-56240,63232,-70850,79130,-88109,97825,-108317,119625,-131790

%N Expansion of (1 - 2*x^2)/(1 + x)^5. Fourth column of Riordan triangle A248156.

%C This is the column k=3 sequence of the Riordan triangle A248156 without the leading three zeros.

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (-5,-10,-10,-5,-1).

%F O.g.f.: (1 - 2*x^2)/(1 + x)^5 = -2/(1 + x)^3 + 4/(1 + x)^4 - 1/(1 + x)^5.

%F a(n) = (-1)^n*(n+1)*(n+2)*(12 + 9*n - n^2)/4!.

%F a(n) =  -5*(a(n-1) + a(n-4)) - 10*(a(n-2) + a(n-3)) - a(n-5), n >= 5, with a(0) =1, a(1) = -5, a(2) = 13, a(3) = -25 and a(4) = 40.

%p A248160:=n->(-1)^n*(n+1)*(n+2)*(12 + 9*n - n^2)/4!: seq(A248160(n), n=0..30); # _Wesley Ivan Hurt_, Oct 09 2014

%t Table[(-1)^n*(n + 1)*(n + 2)*(12 + 9*n - n^2)/4!, {n, 0, 30}] (* _Wesley Ivan Hurt_, Oct 09 2014 *)

%t CoefficientList[Series[(1-2x^2)/(1+x)^5,{x,0,50}],x] (* or *) LinearRecurrence[ {-5,-10,-10,-5,-1},{1,-5,13,-25,40},50] (* _Harvey P. Dale_, Apr 13 2019 *)

%o (PARI) Vec((1 - 2*x^2)/(1 + x)^5 + O(x^50)) \\ _Michel Marcus_, Oct 09 2014

%Y Cf. A248156, A248157 (k=0), A248158 (k=1), A248159 (k=2).

%K sign,easy

%O 0,2

%A _Wolfdieter Lang_, Oct 09 2014