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 A086093 #8 Oct 30 2022 21:38:38
%S A086093 1,5,25,123,593,2803,13017,59531,268705,1199331,5301929,23245819,
%T A086093 101194737,437801939,1883831161,8067412587,34402785089,146158028227,
%U A086093 618862711113,2612502377435,10998603062161,46189948719795,193545427548185,809334701221963,3377982150064353
%N A086093 a(n) = 3^n + 2*n*4^(n-1).
%C A086093 Binomial transform of A084859. Second binomial transform of Cullen numbers A002064.
%H A086093 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (11,-40,48).
%F A086093 G.f.: (1-6*x+10*x^2)/((1-3*x)*(1-4*x)^2).
%F A086093 a(n) = 11*a(n-1) - 40*a(n-2) + 48*a(n-3). - _Wesley Ivan Hurt_, Oct 30 2022
%t A086093 CoefficientList[Series[(1 - 6*x + 10*x^2)/((1 - 3*x)*(1 - 4*x)^2), {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Oct 30 2022 *)
%Y A086093 Cf. A002064, A084859.
%K A086093 easy,nonn
%O A086093 0,2
%A A086093 _Paul Barry_, Jul 10 2003
%E A086093 More terms from _Wesley Ivan Hurt_, Oct 30 2022