Which recurrence relation has the closed form an=n2a_n = n^2an=n2?
an=3an−1−3an−2+an−3a_n = 3a_{n-1} - 3a_{n-2} + a_{n-3}an=3an−1−3an−2+an−3
an=2an−1−an−2a_n = 2a_{n-1} - a_{n-2}an=2an−1−an−2
an=4an−1−4an−2+an−3a_n = 4a_{n-1} - 4a_{n-2} + a_{n-3}an=4an−1−4an−2+an−3
an=an−1+2n−1a_n = a_{n-1} + 2n - 1an=an−1+2n−1