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 A057722 #31 Oct 21 2022 21:09:21 %S A057722 1,-1,5,55,209,551,1189,2255,3905,6319,9701,14279,20305,28055,37829, %T A057722 49951,64769,82655,104005,129239,158801,193159,232805,278255,330049, %U A057722 388751,454949,529255,612305,704759,807301,920639,1045505,1182655 %N A057722 a(n) = n^4 - 3*n^2 + 1. %H A057722 G. C. Greubel, <a href="/A057722/b057722.txt">Table of n, a(n) for n = 0..1000</a> %H A057722 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1). %F A057722 a(0)=1, a(1)=-1, a(2)=5, a(3)=55, a(4)=209, a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). - _Harvey P. Dale_, Nov 22 2012 %F A057722 From _G. C. Greubel_, Aug 12 2019: (Start) %F A057722 G.f.: (1 -6*x +20*x^2 +10*x^3 -x^4)/(1-x)^5. %F A057722 E.g.f.: (1 -2*x +4*x^2 +6*x^3 +x^4)*exp(x). (End) %F A057722 a(n) = A028387(n-2)*A028387(n-1). - _Lamine Ngom_, Oct 27 2020 %p A057722 seq(n^4 -3*n^2 +1, n=0..40); # _G. C. Greubel_, Aug 12 2019 %t A057722 Table[n^4-3n^2+1,{n,0,40}] (* or *) LinearRecurrence[{5,-10,10,-5,1},{1,-1,5,55,209},40] (* _Harvey P. Dale_, Nov 22 2012 *) %t A057722 ((2*Range[0, 40]^2 -3)^2 -5)/4 (* _G. C. Greubel_, Aug 12 2019 *) %o A057722 (PARI) vector(40, n, n--; n^4 -3*n^2 +1) \\ _G. C. Greubel_, Aug 12 2019 %o A057722 (Magma) [n^4 -3*n^2 +1: n in [0..40]]; // _G. C. Greubel_, Aug 12 2019 %o A057722 (Sage) [n^4 -3*n^2 +1 for n in (0..40)] # _G. C. Greubel_, Aug 12 2019 %o A057722 (GAP) List([0..40], n-> n^4 -3*n^2 +1); # _G. C. Greubel_, Aug 12 2019 %Y A057722 Cf. A028387. %K A057722 sign,easy %O A057722 0,3 %A A057722 _N. J. A. Sloane_, Oct 27 2000