A028122 - OEIS

%I #16 Sep 01 2018 01:57:57

%S 1,28,505,7500,100161,1254588,15084745,176531500,2028331921,

%T 23012251548,258784204185,2892049106700,32177076653281,

%U 356869970102908,3948976130302825,43626137399621100,481387456885736241

%N Expansion of 1/((1-4x)(1-5x)(1-8x)(1-11x)).

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (28,-279,1172,-1760)

%F From _Vincenzo Librandi_, Mar 17 2011: (Start)

%F a(n) = 28*a(n-1) - 279*a(n-2) + 1172*a(n-3) - 1760*a(n-4), n >= 4.

%F a(n) = 19*a(n-1) - 88*a(n-2) + 5^(n+1) - 4^(n+1), n >= 2. (End)

%F a(n) = -4^(n+2)/7 - 2*8^(n+2)/9 + 11^(n+3)/126 + 5^(n+3)/18. - _R. J. Mathar_, Mar 18 2011

%t CoefficientList[Series[1/((1-4x)(1-5x)(1-8x)(1-11x)),{x,0,30}],x] (* or *) LinearRecurrence[{28,-279,1172,-1760},{1,28,505,7500},30] (* _Harvey P. Dale_, Apr 01 2013 *)

%K nonn

%O 0,2

%A _N. J. A. Sloane_