74237domain: NAppears in sequencesA255450(2^n-1).at n=8A255451a(n) = a(n-1) + a(n-2) + 3*a(n-4) - 2*a(n-5) for n >= 5, where a(0) = 2, a(1) = 4, a(2) = 8, a(3) = 13, a(4) = 26.at n=17A288925