Which of these is the first three terms of an=an−1+na_n = a_{n-1} + nan=an−1+n with a0=1a_0 = 1a0=1?
1,2,41, 2, 41,2,4
1,1,21, 1, 21,1,2
0,1,30, 1, 30,1,3
1,3,61, 3, 61,3,6