%I #11 Nov 13 2016 14:47:17

%S 6,1,19,25,2801,43,137257,1201,39331,2101,329554457,2353,16148168401,

%T 102943,4956001,2882401,38771752331201,117307,1899815864228857,

%U 1129901,11898664849,247165843,4561457890013486057,5762401,79797014141614001

%N Zsigmondy numbers for a = 7, b = 1: Zs(n, 7, 1) is the greatest divisor of 7^n - 1^n (A024075) that is relatively prime to 7^m - 1^m for all positive integers m < n.

%C By Zsigmondy's theorem, the n-th Zsigmondy number for bases a and b is not 1 except in the three cases (1) a = 2, b = 1, n = 1, (2) a = 2, b = 1, n = 6, (3) n = 2 and a+b is a power of 2.

%H K. Zsigmondy, <a href="http://dx.doi.org/10.1007/BF01692444">Zur Theorie der Potenzreste</a>, Monatsh. f. Math. III. (1892) 265-284.

%Y Cf. A024075, A064078, A064079, A064080, A064081, A064082.

%K nonn

%O 1,1

%A _Jens Voß_, Sep 04 2001

%E More terms from _Vladeta Jovovic_, Sep 06 2001

%E Definition corrected by _Jerry Metzger_, Nov 04 2009