Let a0 = a ∈ N, {Mi} ∞i=1 be an infinite set of integers and {b1, b2, . . . , bk} be a finite set of integers. We say that {ai} ∞i=0is a pseudo-recursive sequence if an+1 = Mn+1an + bjn+1 (bjn+1 ∈ {b1, b2, . . . bk}) holds. In the first part of the paper, we investigate the subset sum of a generalized version of Aα := {an = b2 nαc : n = 0, 1, 2, . . . }, which is a special pseudorecursive sequence. In the second part, we use Aα for an encryption algorithm.