Triangular Numbers and a Sequence

Fill a 4x3 grid with individual digits, such that the three 4digit
numbers and the four 3digit numbers are all
triangular.

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.
Solution
Mail to Ken