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
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
KEYWORD
nonn,fini,full
AUTHOR
Bruno Berselli, Jul 10 2014
STATUS
approved