When I go to BlockExplorer and observe the hash of block 514441's header I see it to be:
However when I obtain the header of block 514441 from:
and I double hash the first 640 bits using Java's SHA256 implementation I get the following (they are byte reversals of each other):
c6 af 0f c1 7d 8e 52 3e c2 9c 19 ab 80 0e dc d3 2c 8b 4d 88 16 c9 4e 00 00 00 00 00 00 00 00 00
Which is the actual block header hash that has to be less than the target value?