50 balls numbered from 1 to 50 are arranged in a row, and now color them as follows: 1 paint 2 balls; 2 the difference between the numbers of the 2 colored balls is greater than 2. If at least one of the two balls colored by one coloring method has a different number from the two balls colored by the other coloring method, the two coloring methods are said to be "different". So how many different coloring methods are there?
编号从1到50的50个球排成一行，现在按照如下方法涂色：1涂2个球；2被涂色的2个球的编号之差大于2．如果一种涂法被涂色的两个球与另一种涂法被涂色的两个球至少有一个是不同号的，这两种涂法就称为"不同的"．那么不同的涂色方法有多少种．
<result>1_138</result>