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 A050947 #9 Dec 17 2016 17:40:21 %S A050947 1,2,3,5,10,15,20,50,100,300,500,1000,2500,5000,10000 %N A050947 Values of Soviet money, 1961-1991 (in kopecks; 100 kopecks = 1 rouble). %C A050947 Notable for quite an unobvious choice of values. Before the hyper-inflation, the sequence ended at 10000 (== 100 roubles), afterwards the sequence follows the 1-2-5-10-20-50 rule %Y A050947 Cf. A051109. %K A050947 fini,full,nonn %O A050947 0,2 %A A050947 _Leonid Broukhis_, Jan 02 2000