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 A147976 #9 Jan 20 2024 13:55:09
%S A147976 -3,-5,-5,25,271,1825,10735,59425,318271,1670785,8656975,44454625,
%T A147976 226827871,1151991745,5830280815,29429454625,148249811071,
%U A147976 745630312705,3745590106255,18797445635425,94264432179871,472428649241665
%N A147976 a(n) = 5^n-4^n-3^n-2^n-1.
%F A147976 G.f.: x*(3-40*x+185*x^2-350*x^3+226*x^4)/((x-1)*(4*x-1)*(3*x-1)*(2*x-1)*(5*x-1)). [Maksym Voznyy (voznyy(AT)mail.ru), Jul 26 2009]
%t A147976 lst={};Do[p=5^n-4^n-3^n-2^n-1^n;AppendTo[lst,p],{n,0,5!}];lst
%t A147976 Table[5^n-4^n-3^n-2^n-1,{n,0,30}] (* _Harvey P. Dale_, Jul 27 2015 *)
%Y A147976 Cf. A147975-A147979.
%K A147976 sign,easy
%O A147976 1,1
%A A147976 _Vladimir Joseph Stephan Orlovsky_, Nov 18 2008
%E A147976 G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.