OFFSET
1,2
COMMENTS
5^5+1 = 3126 = 2*3*521.
6^6+1 = 46657 = 13*37*97.
8^8 = 16777217 = 97*257*673.
MATHEMATICA
Select[Range@46, SquareFreeQ[#^#+1]&]
PROG
(Magma) [ n: n in [1..60] | IsSquarefree(n^n+1) ]; // Bruno Berselli, Mar 24 2011
(PARI) isok(k) = issquarefree(k^k+1); \\ Michel Marcus, Feb 22 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Mar 19 2011
EXTENSIONS
Extended by Bruno Berselli, Mar 24 2011
a(39)-a(78) from Amiram Eldar, Feb 22 2021
STATUS
approved