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 A167386 #30 Mar 19 2024 10:25:34
%S A167386 1,-1,-2,10,-25,49,-84,132,-195,275,-374,494,-637,805,-1000,1224,
%T A167386 -1479,1767,-2090,2450,-2849,3289,-3772,4300,-4875,5499,-6174,6902,
%U A167386 -7685,8525,-9424,10384,-11407,12495,-13650,14874,-16169,17537,-18980,20500,-22099,23779
%N A167386 a(n) = (-1)^n*n*(n+1)*(2*n-5)/6.
%H A167386 Vincenzo Librandi, <a href="/A167386/b167386.txt">Table of n, a(n) for n = 1..10000</a>
%H A167386 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (-4,-6,-4,-1).
%F A167386 a(n) = -4*a(n-1) - 6*a(n-2) - 4*a(n-3) - a(n-4).
%F A167386 G.f.: x*(1+3*x)/(1+x)^4.
%t A167386 Table[n (-1)^n*(n + 1) (2*n - 5)/6, {n, 60}] (* _Vladimir Joseph Stephan Orlovsky_, Jul 08 2011 *)
%o A167386 (PARI) a(n)=(-1)^n*n*(n+1)*(2*n-5)/6 \\ _Charles R Greathouse IV_, Aug 24 2011
%o A167386 (Magma) [(-1)^n*n*(n+1)*(2*n-5)/6: n in [1..50]]; // _Vincenzo Librandi_, Aug 25 2011
%K A167386 sign,easy
%O A167386 1,3
%A A167386 _Jamel Ghanouchi_, Nov 02 2009
%E A167386 Note that for a sequence in which every other term is zero, the OEIS policy is to omit those zeros. - _N. J. A. Sloane_, Nov 08 2009
%E A167386 Zeros removed by skipping even-indexed polynomials - _R. J. Mathar_, Nov 12 2009