@Iamnotawhale You’re correct. The ‘official’ answer to this question is wrong. The question clearly states that the first term of both sequences is 1. Your answer is correct. @admin Please correct the answer to this question!
@thoughtfulmongoose Let a=2x and b=2y, then the question is asking for the GCD of 2x and 4y. Obviously 2 is a common divisor, but we don't know if x has any more 2s in it. If x has one more factor of 2 and y has none then the greatest common divisor is 4. So the answer should be NEI(not enough info)
