A054901 Numbers of the form 2^i*5^j where i+j is even.

1, 4, 10, 16, 25, 40, 64, 100, 160, 250, 256, 400, 625, 640, 1000, 1024, 1600, 2500, 2560, 4000, 4096, 6250, 6400, 10000, 10240, 15625, 16000, 16384, 25000, 25600, 40000, 40960, 62500, 64000, 65536, 100000, 102400, 156250, 160000, 163840