Multiple choice general knowledge math & puzzles Which is the number that comes next in the sequence? 3 1 7 2 13 3 21 4 31 5.... 43 6 52 13 Reveal answer Fill a bubble to check yourself A Correct answer Explanation The sequence alternates: (3, 7, 13, 21, 31) and (1, 2, 3, 4, 5). In the first set, the differences are +4, +6, +8, +10. The next difference is +12, so 31 + 12 = 43.