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 A183855 #8 Mar 30 2012 18:57:12 %S A183855 1,3,5,7,8,9,11,12,13,15,16,17,19,20,21,22,23,25,26,27,28,29,31,32,33, %T A183855 34,35,37,38,39,40,41,42,43,45,46,47,48,49,50,51,53,54,55,56,57,58,59, %U A183855 61,62,63,64,65,66,67,68,69,71,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87,88,89,91,92,93,94,95 %N A183855 n+floor(sqrt(3n-3)); complement of A128422. %Y A183855 Cf. A128422. %K A183855 nonn,easy %O A183855 1,2 %A A183855 _Clark Kimberling_, Jan 07 2011