$T_{0}=0\ ,\ T_{1}=1\ given\ in\ question $
Let's there is
$T{_{2}}=T{_{1}}+T {_{0}}$
$T{_{1}}\ will\ call\ first\ and\ return\ 1\ and\ make\ space\ for \ T{_{0}}$
$it\ means\ T{_{1}}\ and\ T{_{0}}\ will\ share\ same\ space$
$say\ n=4$
$T_{1}$ |
$T_{2}$ |
$T_{3}$ |
$T_{4}$ |
$T_{1}\ and\ T_{0}\ values\ are\ store\ in\ table\ so \ no\ need\ to\ evaluate\ them.$
$in\ this\ question\ maximum\ number\ of\ function\ call\ before\ stack\ overflow\ is\ $
$n*4=48$
n=12