The values of the function at the specified points are:
- \( f(-1) = 4 \)
- \( f(1) = -2 \)
- \( f(4) = 12 \)
- \( f(6) = 18 \)
- \( f(7) = 31 \)
Thus, the final answers are:
\[
\boxed{f(-1) = 4}
\]
\[
\boxed{f(1) = -2}
\]
\[
\boxed{f(4) = 12}
\]
\[
\boxed{f(6) = 18}
\]
\[
\boxed{f(7) = 31}
\]