42584domain: NAppears in sequencesa(1) = 1; thereafter a(n) is the smallest number > a(n-1) which is neither of the form 2*a(i) nor Sum_{j=1..n-1} ( b_j*a(j) ) where 0 < i < n, b_j = 0 or 1.at n=18A331800G.f.: Sum_{n>=0} (1 + x^n*(1+x)^n)^n * x^n.at n=24A337745