A245027 Divisors of 7^12 - 1.

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 13, 15, 16, 18, 19, 20, 24, 25, 26, 30, 32, 36, 38, 39, 40, 43, 45, 48, 50, 52, 57, 60, 65, 72, 75, 76, 78, 80, 86, 90, 95, 96, 100, 104, 114, 117, 120, 129, 130, 144, 150, 152, 156, 160, 171, 172, 180, 181, 190, 195, 200, 208

Offset

1,2

Comments

Number of divisors of k^12-1 for k = 2..20: 24 (2), 80 (3), 96 (4), 240 (5), 128 (6), 864 (7), 512 (8), 384 (9), 256 (10), 1920 (11), 256 (12), 960 (13), 384 (14), 448 (15), 768 (16), 1792 (17), 768 (18), 3840 (19), 384 (20).

The following triangular numbers belong to this sequence: 1, 3, 6, 10, 15, 36, 45, 78, 120, 171, 190, 300, 325, 741, 780, 2080, 2850, 4560, 8385, 14706, 16290, 5915080, 1730160900.

Links

Bruno Berselli, Table of n, a(n) for n = 1..864

Index entries for sequences related to divisors of numbers

Example

13841287200 = 2^5 * 3^2 * 5^2 * 13 * 19 * 43 * 181.

Mathematica

Divisors[7^12 - 1]

Prog

(PARI) divisors(7^12-1)
(Sage) divisors(7^12-1)
(Magma) Divisors(7^12-1);
(Maxima) divisors(7^12-1);

Crossrefs

Cf. Divisors of k^12-1: A003524 (k=2); A003532 (k=4); A003543 (k=8), A027902 (k=9), A027897 (k=10), A245028 (k=11).

Sequence in context: A225857 A168134 A245030 * A065108 A094563 A228897

Adjacent sequences: A245024 A245025 A245026 * A245028 A245029 A245030

Keyword

nonn,fini,full

Author

Bruno Berselli, Jul 10 2014

Status

approved