OFFSET
1,1
COMMENTS
MATHEMATICA
q[n_] := CompositeQ[n] && Divisible[Round[3^n/12], n]; Select[Range[32000], q] (* Amiram Eldar, Feb 09 2022 *)
PROG
(PARI) is(n) = (n>1) && !isprime(n) && (lift(Mod(3, 4*n)^(n-1))==1); \\ Michel Marcus, Feb 09 2022; after A271116
(PARI) list(lim)=my(v=List()); forcomposite(n=91, lim\1, if(bittest(34, n%6) && Mod(3, n)^(n-1)==1, listput(v, n))); Vec(v) \\ Charles R Greathouse IV, Feb 09 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Bill McEachen, Feb 07 2022
STATUS
approved