13728594domain: NAppears in sequencesa(n+3) = 5*a(n+2)-4*a(n+1)+a(n).at n=13A012880a(n) = a(n-1) + Sum_{k=0..n-3} a(k) for n >= 2, a(0)=1, a(1)=2.at n=30A049853Number of positive words of length n in the monoid Br_3 of positive braids on 4 strands.at n=19A097550