359136domain: NAppears in sequencesa(n) = (n + 1)*(n + 2)*(n + 4)*(n + 8)*(n + 15)/120.at n=28A006636a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2 and a(3) = 4.at n=19A049914