A024056 - OEIS

%I #14 Sep 08 2022 08:44:48

%S 1,4,-103,-2062,-15759,-75000,-264311,-745418,-1706527,-2829844,

%T -234375,29340954,208308817,1157954608,5998102121,30346718750,

%U 152319455169,762529114452,3814085045593,19072592456386

%N a(n) = 5^n - n^7.

%H Vincenzo Librandi, <a href="/A024056/b024056.txt">Table of n, a(n) for n = 0..500</a>

%F From _Chai Wah Wu_, Jan 26 2020: (Start)

%F a(n) = 13*a(n-1) - 68*a(n-2) + 196*a(n-3) - 350*a(n-4) + 406*a(n-5) - 308*a(n-6) + 148*a(n-7) - 41*a(n-8) + 5*a(n-9) for n > 8.

%F G.f.: (-6*x^8 - 591*x^7 - 5863*x^6 - 10833*x^5 - 3609*x^4 + 647*x^3 + 87*x^2 + 9*x - 1)/((x - 1)^8*(5*x - 1)). (End)

%o (Magma) [5^n-n^7: n in [0..30]]; // _Vincenzo Librandi_, Jul 03 2011

%K sign,easy

%O 0,2

%A _N. J. A. Sloane_