Here is a table of values of $t$ for integers $0\le n\le 500$, generated using Mathematica's FindRoot.
Here are the first few values:
n= 0: t= 174.7
n= 1: t= 339.8
n= 2: t= 489.7
n= 3: t= 623.7
n= 4: t= 743.3
n= 5: t= 850.4
n= 6: t= 947.2
n= 7: t=1035.4
n= 8: t=1116.4
n= 9: t=1191.3
n= 10: t=1261.0
Here's the rough source code:
Table[{n,
t /. FindRoot[-0.25 == (Sqrt[
2*150^2 -
2*150^2*Cos[
t*0.000072733]] - (t*0.0109170306 + (n*-0.25*.005)))/
0.005, {t, 200 + 150 n}]}, {n, 0, 500}]