The sequence presented is based on the last letters of the English words for numbers. The pattern follows the last letter of each number: E for one, O for two, E for three, R for four, E for five, X for six, N for seven, T for eight. The next term in the sequence is E, corresponding to the last letter of "nine." The reasoning involves identifying the last letters of the spelled-out numbers, which continues with N for ten, E for eleven, and N for twelve, maintaining the established pattern.