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 A165345 #5 Jul 13 2022 12:29:26
%S A165345 1,5,9,25,29,41,53,105,113,129,141,193,205,241,285,433,453,481,497,
%T A165345 553,569,609,653,801,829,881,917,1073,1109,1217,1349,1793,1845,1905,
%U A165345 1933,2001,2029,2081,2129,2281,2313,2369,2409,2569,2609,2721,2853,3297,3357
%N A165345 Number of ON cells after n generations of the 2D cellular automaton described in the comments.
%C A165345 The cells are the squares of the standard square grid. All cells are initially OFF and one cell is turned ON at generation 1. At subsequent generations a cell is ON if and only if (1) it was ON, or (2) exactly one of the four nearest side neighbors was ON, or (3) exactly three of the four nearest corner neighbors were ON, in the previous generation
%C A165345 The equivalent Mathematica automaton is obtained with neighborhood weights {{10,2,10},{2,1,2},{10,2,10}}, rule number 755364134566574, and initial configuration {{1}} (see code).
%H A165345 <a href="https://personal.math.vt.edu/layman/sequences/A165345.html"> Graphs of the automaton for generations 1-20.</a> [From _John W. Layman_, Sep 15 2009]
%t A165345 RasterGraphics[state_?MatrixQ, colors_Integer:2, opts___]:= Graphics[Raster[ Reverse[1 -state/(colors -1)]],AspectRatio-> (AspectRatio /.{opts} /.AspectRatio-> Automatic),Frame-> True, FrameTicks ->none,GridLines->none]; wt = {{10, 2, 10}, {2, 1, 2}, {10, 2, 10}}; rule=755364134566574; init = {{1}}; Show[GraphicsArray[ Map[RasterGraphics, CellularAutomaton[{rule, {2, wt}, {1, 1}}, {init, 0}, 9, -10]]]]; ca = CellularAutomaton[{rule, {2, wt}, {1, 1}}, {init, 0}, 99, -100]; a = Table[Total[ca[[i]], 2], {i, 1, 100}]
%Y A165345 Cf. A048883, A072272, A122108, A160410, A164982.
%K A165345 nonn
%O A165345 1,2
%A A165345 _John W. Layman_, Sep 15 2009, Sep 16 2009