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

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

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