OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
4 is in the sequence because 8 is not in A033948 but 7 and 9 are.
MATHEMATICA
noprQ[n_] := ! IntegerQ @ PrimitiveRoot[n]; q[n_] := noprQ /@ (2*n + {-1, 0, 1}) == {False, True, False}; Select[Range[2, 1000], q] (* Amiram Eldar, Oct 03 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladislav-Stepan Malakhovsky and Juri-Stepan Gerasimov, Jul 20 2010
STATUS
approved