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 A256887 #23 Apr 20 2015 21:00:08 %S A256887 4,9,12,20,25,50,54,56,60,68,88,96,124,125,135,148,150,152,153,156, %T A256887 162,164,169,175,198,207,225,236,242,248,276,279,289,292,325,344,356, %U A256887 375,276,412,425,436,450,488,513,516,585,628,639,688,722,728,764,801,808,847,855,916,948 %N A256887 Squareful numbers that are not the sum of one or more consecutive squarefree numbers. %C A256887 Numbers n such that A242667(n) = 0. %Y A256887 Cf. A005117, A013929, A242667. %K A256887 nonn,easy %O A256887 1,1 %A A256887 _Juri-Stepan Gerasimov_, Apr 20 2015