OFFSET
1,3
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated from the b-file at A049096)
EXAMPLE
8 is in the sequence because 2^8 + 1 = 257 is prime, hence it is squarefree.
9 is not in the sequence because 2^9 + 1 = 513 is divisible by a square, 9.
MATHEMATICA
Select[Range[0, 95], SquareFreeQ[2^# + 1] &] (* Michael De Vlieger, Jun 29 2017 *)
PROG
(PARI) isok(n) = issquarefree(2^n + 1); \\ Michel Marcus, Dec 18 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
0 prepended by Jianing Song, May 28 2024
STATUS
approved