human
Find the nth term rule for ascending quadratic sequences in the form x² + bx + c \(10,21,34,49,66, \ldots\)

When calculating the nth-term rule of this sequence, 
what should replace the triangle?

nth-term rule: \( n^{2} \)\( \color{red}\triangle \)  \(n\) \( \color{purple}\square \) \[
+1
\]
(or just a + sign)
gpt
When finding the nth term rule for a quadratic sequence, believes that the coefficient of n is half the second difference