Question

What is the next number in the following series?
12, 77, 252, 621

Answer 1

Step-by-step explanation:

$series \: 12 \: 77 \: 252 \: 621 \: 1292 \: 2397 \\ 2 ^{4} - 1 = 12 \\ 3^{4} - 1 - = 77 \\ 4^{4} - 1 = 252 \\ 5 ^{4} - 1 = 621$