Source code in the basic programming language

tm = "0"

Function Thue_Morse(s)
	k = ""
	For i = 1 To Length(s)
		If Mid(s, i, 1) = "1" Then
			k += "0"
		Else
			k += "1"
		End If
	Next i
	Thue_Morse = s + k
End Function

Print tm
For j = 1 To 7
	tm = Thue_Morse(tm)
	Print tm
Next j
End

 10 LET T$="0"
 20 PRINT "T0=";T$
 30 FOR I=1 TO 7
 40 PRINT "T";I;"=";
 50 FOR J=1 TO LEN T$
 60 IF T$(J)="0" THEN GOTO 90
 70 LET T$=T$+"0"
 80 GOTO 100
 90 LET T$=T$+"1"
100 NEXT J
110 PRINT T$
120 NEXT I