243685domain: NAppears in sequencesa(n) = (Sum_{j=1..h-1} a(n-j) + a(n-1)*a(n-h+1))/a(n-h) with a(1), ..., a(h)=1, where h = 4.at n=13A283958Number of vertices in regular n-gon after 2 generations of mitosis.at n=39A349967