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 A211002 #14 Oct 02 2013 15:58:41 %S A211002 3,15,31,35,43,47,51,151,155,175,179,243,247,251,255,339,343,347,355, %T A211002 359,363,367,371,391,395,403,407,6571,6575,6583,6587,6591,6595,6599, %U A211002 6603,6607,6611,6615,6619,6623,6627,6631,6635,6655,6659,6675,6679,6683,6687 %N A211002 Numbers congruent to 3 in the structure (or curve) of A211000. %C A211002 The behavior seems to be as modular arithmetic but in a growing structure. For n >= 13 the structure is essentially a column of tangent circles of radius 1. %Y A211002 Cf. A211000, A211001, A211003, A211010, A211011, A211020-211023. %K A211002 nonn %O A211002 1,1 %A A211002 _Omar E. Pol_, Mar 30 2012