RosettaCodeData/Task/Repeat-a-string/PARI-GP/repeat-a-string-3.parigp

repeat(s,n)={
  if(n<4, return(concat(vector(n,i, s))));
  if(n%2,
    Str(repeat(Str(s,s),n\2),s)
  ,
    repeat(Str(s,s),n\2)
  );
}