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 A183569 #10 Jan 27 2023 17:35:50
%S A183569 2,4,6,7,9,10,12,13,14,16,17,18,20,21,22,23,25,26,27,28,30,31,32,33,
%T A183569 34,36,37,38,39,40,42,43,44,45,46,47,49,50,51,52,53,54,56,57,58,59,60,
%U A183569 61,62,64,65,66,67,68,69,70,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87,88,90,91,92,93,94,95,96,97,98,100,101,102,103,104,105,106,107,108,110,111,112,113,114,115,116,117,118,119,121,122,123,124,125,126,127,128,129,130,132,133,134
%N A183569 n+floor(sqrt(4n-3)), complement of A024206.
%t A183569 Table[n+Floor[Sqrt[4n-3]],{n,150}] (* _Harvey P. Dale_, Jan 27 2023 *)
%Y A183569 Cf. A024206.
%K A183569 nonn,easy
%O A183569 1,1
%A A183569 _Clark Kimberling_, Jan 05 2011