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 A086091 #4 Jul 02 2023 18:07:22 %S A086091 1,6,33,171,849,4083,19161,88203,399777,1789155,7923369,34780155, %T A086091 151526385,655905747,2823355257,12093944427,51582654273,219172472259, %U A086091 928100356425,3918172435419,16496161201041,69279692903091 %N A086091 3^n+3n4^(n-1). %C A086091 Binomial transform of A086090 %H A086091 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (11, -40, 48). %F A086091 G.f.: (1-5x+7x^2)/((1-3x)(1-4x)^2) %Y A086091 Cf. A086092. %K A086091 easy,nonn %O A086091 0,2 %A A086091 _Paul Barry_, Jul 09 2003