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 A194360 #7 Mar 30 2012 17:23:02
%S A194360 1,3,5,7,15,21,35,105,9,25,45,49,63,75,147,175,225,245,315,441,525,
%T A194360 735,1225,1575,2205,3675,11025,27,125,135,189,343,375,675,875,945,
%U A194360 1029,1125,1323,1715,2625,3087,3375,4725,5145,6125,6615,7875,8575,9261,15435
%N A194360 Triangle of divisors of 105^n, each number occurring once.
%C A194360 The length of row k is A003215(k), the centered hexagonal numbers, 3k^2 + 3k + 1.
%H A194360 T. D. Noe, <a href="/A194360/b194360.txt">Rows n = 0..20</a>
%e A194360 The triangle has rows beginning with 3^k and ending with 105^k:
%e A194360 1
%e A194360 3, 5, 7, 15, 21, 35, 105
%e A194360 9, 25, 45, 49, 63, 75, 147, 175, 225, 245, 315, 441, 525, 735, 1225, 1575, 2205, 3675, 11025
%t A194360 Join[{{1}}, Table[Complement[Divisors[105^n], Divisors[105^(n-1)]], {n, 9}]]
%Y A194360 Cf. A194356, A194357, A194358, A194359.
%Y A194360 Cf. A108347 (numbers of the form (3^i)*(5^j)*(7^k))
%K A194360 nonn,tabf
%O A194360 0,2
%A A194360 _T. D. Noe_, Sep 08 2011