130383domain: NAppears in sequencesa(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2.at n=20A049891O.g.f.: Sum_{n>=0} n^n * (1+n*x)^(3*n) * x^n/n! * exp(-n*x*(1+n*x)^3).at n=7A218678