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 A265685 #25 Feb 12 2019 02:18:35 %S A265685 1,1,4,6,0,33,39,0,164,335,0,603,2467,0,10412,19692,0,79494,0,155155, %T A265685 1271455,1272243,0 %N A265685 Number of shapes of grid-filling curves of order 4*n+1 (on the square grid) with turns by +-90 degrees that are generated by Lindenmayer-systems with just one symbol apart from the turns. %C A265685 Such curves exist only for n such that 4*n+1 is a term of A057653. %H A265685 Joerg Arndt, <a href="https://arxiv.org/abs/1607.02433">Plane-filling curves on all uniform grids</a>, arXiv preprint arXiv:1607.02433 [math.CO], 2016. %H A265685 Jörg Arndt, Julia Handl, <a href="http://archive.bridgesmathart.org/2018/bridges2018-179.html">Plane-filling Folding Curves on the Square Grid</a>, 2018. (This paper is about a different class of curves where the Lindenmayer-systems have two no-constant symbols) %Y A265685 Cf. A234434 (shapes on the triangular grid), A265686 (tri-hexagonal grid). %Y A265685 Cf. A296148 (folding curves of order n) and A296149 (folding curves of order 4*n+1). %Y A265685 Cf. A306358 (curve orders with at least two decomposition x^2 + y^2). %K A265685 nonn,hard,more %O A265685 1,3 %A A265685 _Joerg Arndt_, Dec 13 2015 %E A265685 a(15)..a(23) from _Joerg Arndt_, Feb 12 2019