What will be the next term in the following series? 8, 15, 28, 53, ?

The series follows the pattern where each term is double the previous term minus 1: 8×2-1=15, 15×2-1=29 (but given as 28, close), 28×2-1=55 (but given as 53), 53×2-1=105. However, checking more carefully: 8×2-1=15, 15×2-2=28, 28×2-3=53, so the pattern appears to be a_n = 2×a_{n-1} - n, giving 53×2-4=102. Or it could simply be doubling minus 1 consistently with slight variations.