jmc

We use the fact that $\lfloor x\rfloor =x-\{x\}$ for all $x.$ Therefore, it suffices to compute the sum of the arithmetic sequence itself, $$1+1.6+2.2+\cdots +100,$$and then subtract off the sum of the fractional parts, $$\{1\}+\{1.6\}+\{2.2\}+\cdots +\{100\}.$$The common difference of the arithmetic sequence is $0.6,$ so the number of terms is $1+\frac{100-1}{0.6}=166.$ Then, the sum of the arithmetic sequence is $$\frac{1+100}{2}\cdot 166=101\cdot 83=8383.$$Because five times the common difference is $5\cdot 0.6=3,$ which is an integer, the fractional parts of the arithmetic sequence repeat every five terms. Thus, the sum of the fractional parts is $$\frac{165}{5}\left(0+0.6+0.2+0.8+0.4\right)+0=33\cdot 2=66.$$Therefore, the given sum equals $$8383-66=\boxed{8317}.$$