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A194360 Triangle of divisors of 105^n, each number occurring once. 1

%I

%S 1,3,5,7,15,21,35,105,9,25,45,49,63,75,147,175,225,245,315,441,525,

%T 735,1225,1575,2205,3675,11025,27,125,135,189,343,375,675,875,945,

%U 1029,1125,1323,1715,2625,3087,3375,4725,5145,6125,6615,7875,8575,9261,15435

%N Triangle of divisors of 105^n, each number occurring once.

%C The length of row k is A003215(k), the centered hexagonal numbers, 3k^2 + 3k + 1.

%H T. D. Noe, <a href="/A194360/b194360.txt">Rows n = 0..20</a>

%e The triangle has rows beginning with 3^k and ending with 105^k:

%e 1

%e 3, 5, 7, 15, 21, 35, 105

%e 9, 25, 45, 49, 63, 75, 147, 175, 225, 245, 315, 441, 525, 735, 1225, 1575, 2205, 3675, 11025

%t Join[{{1}}, Table[Complement[Divisors[105^n], Divisors[105^(n-1)]], {n, 9}]]

%Y Cf. A194356, A194357, A194358, A194359.

%Y Cf. A108347 (numbers of the form (3^i)*(5^j)*(7^k))

%K nonn,tabf

%O 0,2

%A _T. D. Noe_, Sep 08 2011

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Last modified November 11 22:31 EST 2019. Contains 329046 sequences. (Running on oeis4.)