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A109347
Zsigmondy numbers for a = 5, b = 3: Zs(n, 5, 3) is the greatest divisor of 5^n - 3^n (A005058) that is relatively prime to 5^m - 3^m for all positive integers m < n.
9
2, 1, 49, 17, 1441, 19, 37969, 353, 19729, 421, 24325489, 481, 609554401, 10039, 216001, 198593, 381405156481, 12979, 9536162033329, 288961, 18306583, 6125659, 5960417405949649, 346561, 103408180634401, 152787181, 3853528045489, 179655841, 93132223146359169121
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Zsigmondy's Theorem
PROG
(PARI) rad(n) = factorback(factor(n)[, 1])
lista(nn) = {prad = 1; for (n=1, nn, val = 5^n-3^n; d = divisors(val); gd = 1; forstep(k=#d, 1, -1, if (gcd(d[k], prad) == 1, g = d[k]; break)); print1(g, ", "); prad = ra(prad*val); ); } \\ Michel Marcus, Nov 15 2016
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Aug 21 2005
EXTENSIONS
Edited, corrected and extended by Ray Chandler, Aug 26 2005
Definition corrected by Jerry Metzger, Nov 04 2009
More terms from Michel Marcus, Nov 14 2016
STATUS
approved