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 A083331 #7 Jul 02 2023 18:06:27 %S A083331 1,5,26,137,722,3785,19706,101897,523682,2677385,13629386,69136457, %T A083331 349699442,1764742985,8889229466,44709799817,224608392002, %U A083331 1127293880585,5653520131946,28335932715977,141953379225362,710862920970185 %N A083331 a(n) = (3*5^n - 2*4^n + 3^n)/2. %C A083331 Binomial transform of A083330. %H A083331 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12, -47, 60). %F A083331 a(n) = (3*5^n - 2*4^n + 3^n)/2. %F A083331 G.f.: (1-7x+13x^2)/(2(1-3x)(1-4x)(1-5x)). %F A083331 E.g.f.: (3*exp(5x) - 2*exp(4x) + exp(3x))/2. %K A083331 easy,nonn %O A083331 0,2 %A A083331 _Paul Barry_, Apr 27 2003