$47$-smooth Triangular Numbers
A number is $p$-smooth if it has no prime factors larger than $p$.
Let $T$ be the sequence of triangular numbers, i.e. $T(n)=n(n+1)/2$.
Find the sum of all indices $n$ such that $T(n)$ is $47$-smooth.
A number is $p$-smooth if it has no prime factors larger than $p$.
Let $T$ be the sequence of triangular numbers, i.e. $T(n)=n(n+1)/2$.
Find the sum of all indices $n$ such that $T(n)$ is $47$-smooth.