15032385535domain: NAppears in sequencesa(n) = 7*2^n - 1.at n=31A086224a(n) = (n-1)*2^n - 1.at n=28A163383a(n) = 14 * 4^n - 1.at n=15A206372a(n) = 7*2^n + (-1)^n.at n=31A321483