DASH Mining problems - algo DGW, difficulty adjustment.

[HowToMining]

I'm working on a DASH mining profit calculator, and can't prove the difficulty adjustment formula with historical data in explorer.dash.org. Here my proven way, did I miss anything? It really confuse me. 

1.DASH difficulty adjustment formula, nextblockdifficulty = (currentblockdifficulty * 2 + sum(pre 23 blocks difficulty)/25 * ( 24 blocks targetimespan / 24 blocks actualtimespan).
2.I used the block data higher than #34140, which use the algo of DGW.

[comp]

I'm working on a DASH mining profit calculator, and can't prove the difficulty adjustment formula with historical data in explorer.dash.org. Here my proven way, did I miss anything? It really confuse me. 

1.DASH difficulty adjustment formula, nextblockdifficulty = (currentblockdifficulty * 2 + sum(pre 23 blocks difficulty)/25 * ( 24 blocks targetimespan / 24 blocks actualtimespan).
2.I used the block data higher than #34140, which use the algo of DGW.

Isn't that because of the " sort of " first hour premine scam?