This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A024043 #16 Sep 08 2022 08:44:48
%S A024043 1,3,-112,-2123,-16128,-77101,-275840,-807159,-2031616,-4520825,
%T A024043 -8951424,-15292867,-19054592,4360347,163021952,902882449,4026531840,
%U A024043 16769530511,68107256704,273984035205,1098231627776
%N A024043 a(n) = 4^n - n^7.
%H A024043 Vincenzo Librandi, <a href="/A024043/b024043.txt">Table of n, a(n) for n = 0..500</a>
%F A024043 From _Chai Wah Wu_, Jan 26 2020: (Start)
%F A024043 a(n) = 12*a(n-1) - 60*a(n-2) + 168*a(n-3) - 294*a(n-4) + 336*a(n-5) - 252*a(n-6) + 120*a(n-7) - 33*a(n-8) + 4*a(n-9) for n > 8.
%F A024043 G.f.: (-5*x^8 - 471*x^7 - 4672*x^6 - 8417*x^5 - 2418*x^4 + 767*x^3 + 88*x^2 + 9*x - 1)/((x - 1)^8*(4*x - 1)). (End)
%t A024043 Table[4^n-n^7,{n,0,20}] (* _Harvey P. Dale_, Mar 24 2011 *)
%o A024043 (Magma) [4^n-n^7: n in [0..30]]; // _Vincenzo Librandi_, Jul 02 2011
%K A024043 sign,easy
%O A024043 0,2
%A A024043 _N. J. A. Sloane_