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 A245027 Divisors of 7^12 - 1. 3
 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 (list; graph; refs; listen; history; text; internal format)
 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 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

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Last modified September 20 16:30 EDT 2019. Contains 327242 sequences. (Running on oeis4.)