Let ak=250+2k2100. Notice that, for k=0,1,…,49, ak+a100−k=250+2k2100+250+2100−k2100=250+2k2100+2k+250250+k=250. It is clear that for k=0,1,…,49,ak,a100−k∈/Z, so ⌊ak⌋+⌊a100−k⌋=250−1 (since the sum of floors is an integer less than ak+a100−k but greater than ak−1+a100−k−1). Thus, ∑k=0100⌊ak⌋=50⋅(250−1)+249=101⋅249−50.