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 A122039 #15 Dec 17 2024 15:30:40 %S A122039 1,4,9,18,35,68,133,262,519,1032,2057,4106,8203,16396,32781,65550, %T A122039 131087,262160,524305,1048594,2097171,4194324,8388629,16777238, %U A122039 33554455,67108888,134217753,268435482,536870939,1073741852,2147483677 %N A122039 Duplicate of A083706. %Y A122039 Cf. A083706. %K A122039 dead %O A122039 1,2