The classic example is A000396: "Perfect numbers n: n is equal to the sum of the proper divisors of n" and A152953: "a(n) = A136007(n)*(A136007(n)+1)/2."

They are the same if and only if there are no odd perfect numbers.

See also sequences which agree for a long time.

[EDITED] The classic example is A000396: "Perfect numbers n: n is equal to the sum of the proper divisors of n" and A000668(n)*(A000668(n)+1)/2 where A000668 are the Mersenne primes.

They are the same if and only if there are no odd perfect numbers.

See also sequences which agree for a long time.

For example, A000396: "Perfect numbers n: n is equal to the sum of the proper divisors of n" and A006516: a(n) = 2^(n-1)*(2^n - 1), n >= 0.

The classic example is A000396: "Perfect numbers n: n is equal to the sum of the proper divisors of n" and A152953: "a(n) = A136007(n)*(A136007(n)+1)/2."

They are the same if and only if there are no odd perfect numbers.

See also sequences which agree for a long time.