Given d1=17d_1 = 17d1=17, d2=18d_2 = 18d2=18, and dn=dn−1+dn−2d_n = d_{n-1} + d_{n-2}dn=dn−1+dn−2 for ngeq3n \\geq 3ngeq3, what is d4d_4d4?
525252
535353
363636
707070