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 A027928 #37 Sep 08 2022 08:44:49
%S A027928 1,3,8,20,46,97,189,344,591,967,1518,2300,3380,4837,6763,9264,12461,
%T A027928 16491,21508,27684,35210,44297,55177,68104,83355,101231,122058,146188,
%U A027928 174000,205901,242327,283744,330649,383571,443072
%N A027928 a(n) = T(n, 2*n-5), T given by A027926.
%H A027928 Vincenzo Librandi, <a href="/A027928/b027928.txt">Table of n, a(n) for n = 3..1000</a>
%H A027928 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1).
%F A027928 a(n) = (n-2)*(n^4 - 8*n^3 + 39*n^2 - 92*n + 180)/120.
%F A027928 a(n) = C(n,n-1) + C(n+1,n-2) + C(n+2,n-3) with offset 1. - _Zerinvary Lajos_, May 29 2007
%F A027928 G.f.: x^3*(1 - 3*x + 5*x^2 - 3*x^3 + x^4)/(1-x)^6. - _Colin Barker_, Mar 18 2012
%F A027928 E.g.f.: 3 + x -(360 - 240*x + 60*x^2 - 20*x^3 - x^5)*exp(x)/120. - _G. C. Greubel_, Sep 06 2019
%p A027928 seq(binomial(n,n-1)+binomial(n+1,n-2)+binomial(n+2,n-3), n=1..35); # _Zerinvary Lajos_, May 29 2007
%t A027928 CoefficientList[Series[(1-3*x+5*x^2-3*x^3+x^4)/(1-x)^6,{x,0,40}],x] (* _Vincenzo Librandi_, Apr 22 2012 *)
%o A027928 (Magma) [(n-2)*(n^4-8*n^3+39*n^2-92*n+180)/120: n in [3..40]]; // _Vincenzo Librandi_, Apr 22 2012
%o A027928 (PARI) vector(40, n, m=n+2; n*(m^4 -8*m^3 +39*m^2 -92*m +180)/120) \\ _G. C. Greubel_, Sep 06 2019
%o A027928 (Sage) [(n-2)*(n^4 -8*n^3 +39*n^2 -92*n +180)/120 for n in (3..40)] # _G. C. Greubel_, Sep 06 2019
%o A027928 (GAP) List([3..40], n-> (n-2)*(n^4 -8*n^3 +39*n^2 -92*n +180)/120); # _G. C. Greubel_, Sep 06 2019
%Y A027928 Cf. A228074, A000045.
%K A027928 nonn,easy
%O A027928 3,2
%A A027928 _Clark Kimberling_