OFFSET
1,1
EXAMPLE
2383^4 - 1 = 2^6*3*5*149*157*397*3617, 2383^4 + 1 = 2*809*857*2833*8209 and 4*2383 > 8209 and 4*2383 > 3617.
MATHEMATICA
Select[Prime[Range[PrimePi[200000]]], 4 # > FactorInteger[#^4 - 1][[-1, 1]] && 4 # > FactorInteger[#^4 + 1][[-1, 1]] &] (* T. D. Noe, Nov 07 2012 *)
PROG
(PARI) forprime(h=3, 200001, for(n=4, 4, a=h^n; b=a-1; c=a+1; d=vecmax(factor(b)[, 1]~); e=vecmax(factor(c)[, 1]~); g=h*n; if(g>d && g>e, print1(h, ", "))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Robin Garcia, Nov 07 2012
STATUS
approved