4.3BSD/usr/contrib/icon/book/f/qseq.icn

procedure qseq()
   local i, qmem
   qmem := table()
   suspend qmem[1 | 2] := 1
   i := 2
   repeat suspend qmem[i +:= 1] :=
      qmem[i - qmem[i - 1]] + qmem[i - qmem[i - 2]]
end