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 A194359 #13 Sep 03 2020 13:19:04
%S A194359 1,2,3,5,6,7,10,14,15,21,30,35,42,70,105,210,4,9,12,18,20,25,28,36,45,
%T A194359 49,50,60,63,75,84,90,98,100,126,140,147,150,175,180,196,225,245,252,
%U A194359 294,300,315,350,420,441,450,490,525,588,630,700,735,882,900
%N A194359 Triangle of divisors of 210^n, each number occurring once.
%C A194359 The length of row k is A005917, the rhombic dodecahedral numbers, (k+1)^4 - k^4. The triangle has rows beginning with 2^k and ending with 210^k.
%H A194359 T. D. Noe, <a href="/A194359/b194359.txt">Rows n = 0..9</a>
%t A194359 Join[{{1}}, Table[Complement[Divisors[210^n], Divisors[210^(n-1)]], {n, 9}]]
%t A194359 Take[DeleteDuplicates[Flatten[Divisors/@(210^Range[5])]],100] (* _Harvey P. Dale_, Sep 03 2020 *)
%Y A194359 Cf. A018336, A194356, A194357, A194358.
%K A194359 nonn,tabf
%O A194359 0,2
%A A194359 _T. D. Noe_, Aug 26 2011