41590domain: NAppears in sequencesa(n) = 9*a(n-1) + 33*a(n-2) - 76*a(n-3) - 33*a(n-4) + 9*a(n-5) + a(n-6), a(0)=a(1)=1, a(2)=2, a(3)=35, a(4)=312, a(5)=3779.at n=6A055519Starts of runs of 3 consecutive Catalan-Niven numbers (A352508).at n=14A352510