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 A048508 #17 Sep 08 2022 08:44:57 %S A048508 1,17,58,160,408,1000,2392,5624,13048,29944,68088,153592,344056, %T A048508 765944,1695736,3735544,8191992,17891320,38928376,84410360,182452216, %U A048508 393215992,845152248,1811939320,3875536888,8271167480,17616076792 %N A048508 a(n) = T(3,n), array T given by A048505. %C A048508 n-th difference of a(n), a(n-1), ..., a(0) is (16, 25, 36, 49, 64, ...). %H A048508 Vincenzo Librandi, <a href="/A048508/b048508.txt">Table of n, a(n) for n = 0..2000</a> %H A048508 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (7,-18,20,-8). %F A048508 a(n) = (n+4)*(n+9) * 2^(n-2) - 8. - _Ralf Stephan_, Feb 05 2004 %F A048508 a(n) = 7*a(n-1)-18*a(n-2)+20*a(n-3)-8*a(n-4). - _Colin Barker_, Feb 25 2015 %F A048508 G.f.: (40*x^3-43*x^2+10*x+1) / ((x-1)*(2*x-1)^3). - _Colin Barker_, Feb 25 2015 %o A048508 (Magma) [(n+4)*(n+9) * 2^(n-2) - 8: n in [0..30]]; // _Vincenzo Librandi_, Sep 26 2011 %o A048508 (PARI) Vec((40*x^3-43*x^2+10*x+1) / ((x-1)*(2*x-1)^3) + O(x^100)) \\ _Colin Barker_, Feb 25 2015 %K A048508 nonn,easy %O A048508 0,2 %A A048508 _Clark Kimberling_