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 A111300 #21 Feb 15 2015 16:34:12
%S A111300 0,1,2,5,6,7,12,13,14,33,40,45,46,47,57,90,97,102,103,104,279,336,369,
%T A111300 376,381,382,383,561,840,897,930,937,942,943,944,2895,3456,3735,3792,
%U A111300 3825,3832,3837,3838,3839,6555,9450,10011,10290,10347,10380,10387,10392
%N A111300 Positive integers that are the difference between two double factorials.
%H A111300 T. D. Noe, <a href="/A111300/b111300.txt">Table of n, a(n) for n = 1..1000</a>
%F A111300 M!! - N!! where M and N positive integers.
%e A111300 7!! - 4!! = 7*5*3*1 - 4*2 = 105 - 8 = 97.
%e A111300 9!! - 5!! = 9*7*5*3*1 - 5*3*1 = 945 - 15 = 930.
%t A111300 terms[n_]:=Sort[Union[Flatten[Table[j!!-i!!,{i,n},{j,i,n}]]]]; terms[12] (* _Enrique Pérez Herrero_, May 21 2011 *)
%Y A111300 Cf. A006882 (n!!).
%K A111300 easy,nonn
%O A111300 1,3
%A A111300 _Paolo P. Lava_ and _Giorgio Balzarotti_, Nov 02 2005
%E A111300 Extended by _T. D. Noe_, May 22 2011