I3.4 For the sequence $1,2,1,2,2,1,2,2,2,1,2,2,2,2,1,2, \ldots$, determine the sum $\delta$ of the first $\gamma$ terms.
$\begin{array}{l}\delta=1+2+1+2+2+1+2+2+2+1+2+2+2+2+1+2+\ldots+2+(5 \text { terms })+1+2+ \\ \ldots+2 \text { (6 terms })+1+2+\ldots+2 \text { (7 terms })+1+2+\ldots+2 \text { (8 terms })+1 \\ =9+2 \times 36=81\end{array}$