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A194360 Triangle of divisors of 105^n, each number occurring once. 1
1, 3, 5, 7, 15, 21, 35, 105, 9, 25, 45, 49, 63, 75, 147, 175, 225, 245, 315, 441, 525, 735, 1225, 1575, 2205, 3675, 11025, 27, 125, 135, 189, 343, 375, 675, 875, 945, 1029, 1125, 1323, 1715, 2625, 3087, 3375, 4725, 5145, 6125, 6615, 7875, 8575, 9261, 15435 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

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

LINKS

T. D. Noe, Rows n = 0..20

EXAMPLE

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

1

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

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

MATHEMATICA

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

CROSSREFS

Cf. A194356, A194357, A194358, A194359.

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

Sequence in context: A014865 A018617 A018286 * A057743 A071169 A172235

Adjacent sequences:  A194357 A194358 A194359 * A194361 A194362 A194363

KEYWORD

nonn,tabf

AUTHOR

T. D. Noe, Sep 08 2011

STATUS

approved

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Last modified October 21 14:45 EDT 2019. Contains 328301 sequences. (Running on oeis4.)