OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
EXAMPLE
4 is in this sequence because 5^7 - 4^7 = 61741 = 29*2129.
MATHEMATICA
Select[Range[100], ! PrimeQ[(# + 1)^7 - #^7] &]
PROG
(Magma) [n: n in [0..350] | not IsPrime((n+1)^7-n^7)];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 20 2014
STATUS
approved