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 A089544 #3 Mar 30 2012 17:29:13 %S A089544 2,2,11,37,59,1609,2333,10831,46381,1428571429,17956553,5271373, %T A089544 872838923897,165850848142657,399174011286107,67280421310721, %U A089544 19238145625263645679,2083719670141,29528651577019605807821 %N A089544 Greater prime factor of semiprimes in A089542. %Y A089544 Cf. A085753, A089542, A089543. %K A089544 nonn %O A089544 1,1 %A A089544 _Ray Chandler_, Nov 09 2003