42598982984domain: NAppears in sequencesa_{k+1} = 6*a_k + 11*a_{k-1} - 19*a_{k-2} - 4*a_{k-3} + a_{k-4}, a_1=1, a_2=2, a_3=19, a_4=118, a_5=875.at n=13A055518