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 A299776 #11 Dec 14 2018 19:52:06 %S A299776 0,1,5,9,21,25,37,49,77,89,101,113,141,161,189,225,293,329,341,353, %T A299776 381,401,429,465,533,577,605,641,709,777,853,945,1101,1209,1237,1249, %U A299776 1277,1297,1325,1361,1429,1473,1501,1537,1605,1673,1749,1841,1997,2113,2157 %N A299776 a(n) = 1 + 4*(A160120(n) - 1)/3. %C A299776 Essentially this should be the 120-degree wedge of the cellular automaton of A160120 projected in four quadrants. %C A299776 First differs from both A147552 and A160720 at a(9). %H A299776 Shawn A. Broyles, <a href="/A299776/b299776.txt">Table of n, a(n) for n = 0..1000</a> %Y A299776 Cf. A139250, A147552, A160120. A160720. %K A299776 nonn %O A299776 0,3 %A A299776 _Omar E. Pol_, Apr 03 2018