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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

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

Cf. A218833, A218834, A218863.

Sequence in context: A031626 A117921 A052357 * A164521 A251153 A305500

Adjacent sequences:  A218905 A218906 A218907 * A218909 A218910 A218911

KEYWORD

nonn

AUTHOR

Robin Garcia, Nov 08 2012

STATUS

approved

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)