login
a(n) = 8^n - n^5.
2

%I #13 Nov 12 2022 20:07:31

%S 1,7,32,269,3072,29643,254368,2080345,16744448,134158679,1073641824,

%T 8589773541,68719227904,549755442595,4398045973280,35184371329457,

%U 281474975662080,2251799812265391,18014398507592416,144115188073379773,1152921504603646976

%N a(n) = 8^n - n^5.

%H Vincenzo Librandi, <a href="/A024093/b024093.txt">Table of n, a(n) for n = 0..400</a>

%F From _Chai Wah Wu_, Jul 10 2016: (Start)

%F a(n) = 14*a(n-1) - 63*a(n-2) + 140*a(n-3) - 175*a(n-4) + 126*a(n-5) - 49*a(n-6) + 8*a(n-7) for n > 6.

%F G.f.: (-9*x^6 - 201*x^5 - 517*x^4 - 122*x^3 + 3*x^2 + 7*x - 1)/((x - 1)^6*(8*x - 1)). (End)

%t CoefficientList[Series[(-9*x^6 - 201*x^5 - 517*x^4 - 122*x^3 + 3*x^2 + 7*x - 1)/((x - 1)^6*(8*x - 1)), {x, 0, 20}], x] (* _Wesley Ivan Hurt_, Nov 12 2022 *)

%o (Magma) [8^n-n^5: n in [0..20]]; // _Vincenzo Librandi_, Jul 05 2011

%K nonn

%O 0,2

%A _N. J. A. Sloane_