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 A192306 #12 Aug 23 2025 17:57:27 %S A192306 0,4,10,26,56,116,228,436,814,1494,2704,4840,8584,15108,26418,45938, %T A192306 79496,136988,235180,402420,686550,1168174,1982880,3358416,5676816, %U A192306 9578116,16133338,27132746,45565784,76419524,128006004,214167220,357935614 %N A192306 1-sequence of reduction of (2n) by x^2 -> x+1. %C A192306 See A192232 for definition of "k-sequence of reduction of [sequence] by [substitution]". %F A192306 a(n) = 2*A122491(n+1). %F A192306 G.f.: 2*x^2*(2-x)/((1-x)*(1-x-x^2)^2). - _Colin Barker_, Feb 11 2012 %t A192306 (* See A192305. *) %Y A192306 Cf. A192232, A192305, A122491. %K A192306 nonn,easy,changed %O A192306 1,2 %A A192306 _Clark Kimberling_, Jun 27 2011