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 A127404 #3 Mar 31 2012 10:29:10 %S A127404 2,2,6,10,16,20,34,36,50,58,72,86,106,116,138,154,176,190,222,234,270, %T A127404 292 %N A127404 Number of points in a honeycomb net covered by a circular disk of diameter n if the center of the circle is chosen at mid-edge between two grid points. %e A127404 a(1)=2 because a disk of diameter 1 centered at the middle of an edge covers the 2 net points bounding this edge. %Y A127404 Cf. A127402, A127403, A127405, A127406. The corresponding sequences for the square lattice and hexagonal lattice are A053414 and A053417, respectively. %K A127404 more,nonn %O A127404 1,1 %A A127404 _Hugo Pfoertner_, Feb 08 2007