The given sequence appears to be a sequence of triangular numbers:
1 = 1
3 = 1 + 2
6 = 1 + 2 + 3
10 = 1 + 2 + 3 + 4
15 = 1 + 2 + 3 + 4 + 5
To find the tenth term, we can use the formula for the nth triangular number:
Tn = n(n+1)/2
For the 10th term:
T10 = 10(10+1)/2
= 10(11)/2
= 55
So, the tenth term of the sequence is:
55