Ruby code - 5 lines

Link:

Ruby, pasted on Jul 12:

4.times{|i|
    col = i+1
    row = i+1
    print "m1._4#{col} * m2._#{row}1 + "
}

Output:

1	m1._41 * m2._11 + m1._42 * m2._21 + m1._43 * m2._31 + m1._44 * m2._41 +