A1F = 1010 0001 1111 = 1+2+4+8+16+512+2048 = 2 591
F4 = 1111 0100 = 4 + 16 + 32 + 64+ 128 = 244
ABC = 1010 1011 1100 = 4 + 8 + 16 + 32 + 128 + 512 + 2048 = 2 748
2021 = 1024 + 512 + 256 + 128 + 64 + 32 + 4 + 1 = 0111 1110 0101 = 7E5
123 = 64 + 32 + 16 + 8 + 2 + 1 = 0111 1011 = 7B
257 = 256 + 1 = 0001 0000 0001 = 101