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 A193176 #6 Mar 30 2012 16:52:03 %S A193176 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,25,27,30, %T A193176 33,35,42,45 %N A193176 A193175(n)/2. %D A193176 Mermin, N. David; Rokhsar, Daniel S.; and Wright, David C.; Beware of 46-fold symmetry: the classification of two-dimensional quasicrystallographic lattices. Phys. Rev. Lett. 58 (1987), 2099-2101. %Y A193176 Cf. A193175. %K A193176 nonn,fini,full %O A193176 1,1 %A A193176 _N. J. A. Sloane_, Jul 17 2011