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 A122226 #4 Mar 31 2012 10:29:10 %S A122226 1,7,10,19,24,37,48,61 %N A122226 Length of the longest possible self-avoiding path on the 2-dimensional triangular lattice such that the path fits into a circle of diameter n. %C A122226 The path may be open or closed. For larger n several solutions with the same number of segments exist. %C A122226 It is conjectured that the sequence is identical with A125852 for all n>1. That means that it is always possible to find an Hamiltonian cycle on the maximum possible number of lattice points that can be covered by circular disks of diameter >=2. For the given additional terms it was easily possible to construct such closed paths by hand, using the lattice subset found by the exhaustive search for A125852. See the examples at the end of the linked pdf file a122226.pdf that were all generated without using a program. - _Hugo Pfoertner_, Jan 12 2007 %H A122226 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a122226.pdf">Examples of compact self avoiding paths on a triangular lattice</a>. %Y A122226 Cf. A003215, A004016; A125852 gives upper bounds for a(n). %Y A122226 Cf. A122223, A122224. %K A122226 hard,more,nonn %O A122226 1,2 %A A122226 _Hugo Pfoertner_, Sep 25 2006 %E A122226 a(7) and a(8) from _Hugo Pfoertner_, Dec 11 2006