The sequence of triangle numbers is generated by adding the natural numbers. So
the $7$th triangle number would be $1 + 2 + 3 + 4 + 5 + 6 + 7 = 28$.
The first ten terms would be:
$$1, 3, 6, 10, 15, 21, 28, 36, 45, 55, \dots$$
Let us list the factors of the first seven triangle numbers:
$$\begin{align}
\mathbf 1 &\colon 1\\\
\mathbf 3 &\colon 1,3\\\
\mathbf 6 &\colon 1,2,3,6\\\
\mathbf{10} &\colon 1,2,5,10\\\
\mathbf{15} &\colon 1,3,5,15\\\
\mathbf{21} &\colon 1,3,7,21\\\
\mathbf{28} &\colon 1,2,4,7,14,28
\end{align}$$
We can see that $28$ is the first triangle number to have over five divisors.
What is the value of the first triangle number to have over five hundred
divisors?
ProjectEuler+ Problem Statement
The Project Euler problem is equivalent to the ProjectEuler+ challenge with
$T = 1$ and $N = 500$.