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A218908
Primes p such that k*p is greater than the greatest prime factor of p^k - 1 and p^k + 1 for k = 1 to k = 4.
0
3373, 41893, 62497, 105557, 165701, 201577, 208877, 239803, 302399, 333107
OFFSET
1,1
EXAMPLE
The greatest factors of 3373^4 - 1 , 3373^6 - 1 and 3373^8 - 1 are respectively: 317, 6379, 7369.
PROG
(PARI) forprime(h=3, 400000, f=h^3-1; g=h^3+1; k=vecmax(factor(f)[, 1]~); l=vecmax(factor(g)[, 1]~); m=h^4-1; n=h^4+1; o=vecmax(factor(m)[, 1]~); p=vecmax(factor(n)[, 1]~); if(3*h>k && 3*h>l && 4*h>o && 4*h>p, print1(h, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Robin Garcia, Nov 08 2012
STATUS
approved