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 A084847 #12 May 09 2024 04:41:14 %S A084847 1,4,18,86,418,2022,9650,45334,209730,956870,4312402,19228662, %T A084847 84948962,372287398,1620178674,7008019670,30150864514,129107299206, %U A084847 550530654866,2338786731958,9902578218786,41802362561894,175984622563378 %N A084847 a(n) = 2*3^n+2^(2n-1)*(n-2). %C A084847 Binomial transform of A084643. Third binomial transform of abs(A060747). %H A084847 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (11,-40,48). %F A084847 G.f.: (1-7x+14x^2)/((1-3x)(1-4x)^2). %Y A084847 Cf. A060747, A084643. %K A084847 easy,nonn %O A084847 0,2 %A A084847 _Paul Barry_, Jun 09 2003