A recurrence to relate to
Algebra
Level
4
\[ \large a_{n+2} = (n + 3)a_{n+1} - (n + 2)a_{n} \]
For whole numbers \(n\), consider the recurrence relation defined as above with \(a_{1} = 1, a_{2} = 3\).
Find \(\displaystyle\bigg( \sum_{k=1}^{2015} a_{k} \bigg)\pmod{100}.\)
by
Brian Charlesworth