8388631domain: NAppears in sequencesa(n) = 2^n + n.at n=23A006127Semiprimes of the form 2^k + k.at n=2A089535Where powers of 2 occur in the union of squares and powers of 2.at n=46A188917a(n) = 2^prime(n) + prime(n).at n=8A243139