OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
ok[1]=True; ok[n_]:=And@@(Mod[#, 5]==4&)/@FactorInteger[n][[All, 1]]; Select[Range[4000], ok] (* Vincenzo Librandi, Aug 20 2012 *)
PROG
(Magma) [n: n in [1..1100] | forall{d: d in PrimeDivisors(n) | d mod 5 eq 4}]; // Vincenzo Librandi, Aug 20 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved