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A194359 Triangle of divisors of 210^n, each number occurring once. 2

%I #13 Sep 03 2020 13:19:04

%S 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 49,50,60,63,75,84,90,98,100,126,140,147,150,175,180,196,225,245,252,

%U 294,300,315,350,420,441,450,490,525,588,630,700,735,882,900

%N Triangle of divisors of 210^n, each number occurring once.

%C 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 T. D. Noe, <a href="/A194359/b194359.txt">Rows n = 0..9</a>

%t Join[{{1}}, Table[Complement[Divisors[210^n], Divisors[210^(n-1)]], {n, 9}]]

%t Take[DeleteDuplicates[Flatten[Divisors/@(210^Range[5])]],100] (* _Harvey P. Dale_, Sep 03 2020 *)

%Y Cf. A018336, A194356, A194357, A194358.

%K nonn,tabf

%O 0,2

%A _T. D. Noe_, Aug 26 2011

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Last modified April 18 18:20 EDT 2024. Contains 371781 sequences. (Running on oeis4.)