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Numbers k such that k^3 divides 17^(k^2) - 1.
17

%I #22 Jun 06 2021 02:43:08

%S 1,2,4,6,8,10,12,16,18,20,24,30,36,40,42,48,58,60,72,78,80,84,90,110,

%T 114,116,120,126,144,156,168,174,180,210,220,222,228,232,234,240,252,

%U 290,312,330,336,342,348,360,390,420,440,444,456,464,468,504,522,546

%N Numbers k such that k^3 divides 17^(k^2) - 1.

%C The first 9 terms (and others) of A218087 are in this sequence A177917 as well as in A128397. These two sequences have many terms in common, but A177917 \ A128397 = {10, 30, 58, 90, 110, ...} and A128397 \ A177917 = {580, 624, 660, 684, 696, 720, ...}. - _M. F. Hasler_, Oct 22 2012

%H Robert Price, <a href="/A177917/b177917.txt">Table of n, a(n) for n = 1..6436</a>

%t Select[Range[600],Divisible[17^#^2-1,#^3]&] (* _Harvey P. Dale_, Jul 19 2015 *)

%o (PARI) is_A177917(n)=Mod(17,n^3)^(n^2)==1 \\ _M. F. Hasler_, Oct 21 2012

%Y Cf. A129211, A129212, A177905, A177907, A127102, A177909, A177243, A177911, A177912, A177913, A177914, A177915, A177916, A177918, A177919, A177920.

%Y Cf. A127103, A127104, A127105, A127106, A127107, A127102, A127101, A127100, A127092, ..., A128397.

%K nonn

%O 1,2

%A _Alexander Adamchuk_, May 14 2010