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 A033159 #12 Jul 08 2025 19:42:40 %S A033159 2,3,5,6,11,12,14,15,29,30,32,33,38,39,41,42,83,84,86,87,92,93,95,96, %T A033159 110,111,113,114,119,120,122,123,245,246,248,249,254,255,257,258,272, %U A033159 273,275,276,281,282,284,285,326,327,329,330,335,336,338,339,353,354,356,357,362 %N A033159 Begins with (2, 3); avoids 3-term arithmetic progressions. %D A033159 Iacobescu, F. 'Smarandache Partition Type and Other Sequences.' Bull. Pure Appl. Sci. 16E, 237-240, 1997. %D A033159 H. Ibstedt, A Few Smarandache Sequences, Smarandache Notions Journal, Vol. 8, No. 1-2-3, 1997, 170-183. %H A033159 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NonarithmeticProgressionSequence.html">Nonarithmetic Progression Sequence</a> %Y A033159 a(n) = A003278(n)+1 %K A033159 nonn %O A033159 1,1 %A A033159 _N. J. A. Sloane_