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 A091702 #13 May 04 2023 06:06:19 %S A091702 1,2,7,23,78,264,895,3034,10286,34872,118225,400813,1358859,4606881, %T A091702 15618510,52950761,179516682,608607667,2063336333,6995240208, %U A091702 23715661274,80402183905,272584057514,924129977596,3133038018732,10621803712455,36010643162123 %N A091702 Column 0 of triangle A091700. %H A091702 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,2,-2,-1). %F A091702 G.f.: (1-x-x^2)/(1-3x-2x^2+2x^3+x^4). %F A091702 From _Philippe Deléham_, May 04 2023: (Start) %F A091702 a(n) = 3*a(n-1) + 2*a(n-2) - 2*a(n-3) - a(n-4), for n>3. %F A091702 a(n) = M^n [1, 1] where M = [2, 1, 1, 1 ; 1, 1, 1, 0 ; 1, 1, 0, 0 ; 1, 0, 0, 0 ] . (End) %Y A091702 Cf. A091700. %K A091702 nonn,easy %O A091702 0,2 %A A091702 _Christian G. Bower_, Jan 29 2004