Triangular Numbers and a Sequence

1. Fill a 4x3 grid with individual digits, such that the three 4-digit numbers and the four 3-digit numbers are all triangular.
2. What are the last two numbers in this sequence?
   10, 11, 12, 13, 14, 15, 16, 17, 20, 22, 24, 31, 100, 121, ..?.., ..?..

Source: 1. Reader Hareendra Yalamanchili (later found at www.mathpuzzle.com for April 22.) 2. Reader Peter Bentley.