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.

3373, 41893, 62497, 105557, 165701, 201577, 208877, 239803, 302399, 333107

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