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 A117628 #8 Jan 02 2015 22:07:45 %S A117628 0,2,16,112,832,6912,62784,623232 %N A117628 Let f(n) = average number of comparisons needed for sorting n elements using merge insertion. Sequence gives n!*f(n). %D A117628 D. E. Knuth, TAOCP, Vol. 3, Section 5.3.1. %Y A117628 A117627 is a lower bound for any comparison-based sorting algorithm. %K A117628 nonn %O A117628 1,2 %A A117628 _N. J. A. Sloane_, Oct 06 2006