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 A126423 #14 Aug 30 2025 15:56:28
%S A126423 -1,13,77,251,619,1289,2393,4087,6551,9989,14629,20723,28547,38401,
%T A126423 50609,65519,83503,104957,130301,159979,194459,234233,279817,331751,
%U A126423 390599,456949,531413,614627,707251,809969,923489,1048543,1185887,1336301,1500589,1679579,1874123,2085097,2313401,2559959
%N A126423 a(n) = n^4 - n - 1.
%H A126423 Vincenzo Librandi, <a href="/A126423/b126423.txt">Table of n, a(n) for n = 1..10000</a>
%H A126423 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).
%F A126423 From _Elmo R. Oliveira_, Aug 29 2025: (Start)
%F A126423 G.f.: x*(-1 + 18*x + 2*x^2 + 6*x^3 - x^4)/(1-x)^5.
%F A126423 E.g.f.: 1 + (-1 + 7*x^2 + 6*x^3 + x^4)*exp(x).
%F A126423 a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n > 5. (End)
%t A126423 a = {}; Do[AppendTo[a, x^4 - x - 1], {x, 1, 100}]; a
%o A126423 (Magma) [n^4-n-1: n in [1..40]]; // _Vincenzo Librandi_, Aug 30 2011
%Y A126423 Cf. A002327, A002328, A116581, A126420, A126421, A126422.
%K A126423 sign,easy,changed
%O A126423 1,2
%A A126423 _Artur Jasinski_, Dec 26 2006