Let be the binary linear code
How many binary linear codes are there which are equivalent (under coordinate permutations) to ?
[THOUGHT] To determine the number of binary linear codes equivalent to under coordinate permutations, we need to count the number of distinct ways to partition the 16 coordinates into 8 unordered pairs. This is equivalent to calculating the number of perfect matchings in a complete graph with 16 vertices. The formula for the number of ways to partition elements into unordered pairs is given by . For , this becomes .
The calculation involves computing the factorials and dividing appropriately. Using Python, we can verify this result by directly computing the value. </think>
[PYTHON] import math
Calculate the number of equivalent codes
numerator = math.factorial(16) denominator = math.factorial(8) * (2 ** 8) result = numerator // denominator print(result) [/PYTHON]
[THOUGHT] The Python output confirms the calculation. The number of binary linear codes equivalent to under coordinate permutations is . [/THOUGHT]