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 A234947 #5 Jan 08 2014 23:17:57 %S A234947 1,3,12,8,21,720,4079,3040,20505,1669221,14708525,10567748 %N A234947 Number of different optimal triangle difference sets M(n,2). %H A234947 J. B. Shearer, <a href="http://www.research.ibm.com/people/s/shearer/dtsopt.html">Difference Triangle Sets: Known optimal solutions</a>. %H A234947 J. B. Shearer, <a href="http://www.research.ibm.com/people/s/shearer/dtslb.html">Difference Triangle Sets: Discoverers</a> %Y A234947 A row of array in A234944. Cf. A234943. %K A234947 nonn %O A234947 1,2 %A A234947 _N. J. A. Sloane_, Jan 08 2014