That's the correct formula since the homestead development phase.
100000 is here a constant and according to How does the Ethereum Homestead difficulty adjustment algorithm work? :
+ int(2**((block.number // 100000) - 2))
The difficulty bomb part, which increases the difficulty exponentially every 100,000 blocks.
It seems this formula is no longer correct since the EIP-2384 : https://eips.ethereum.org/EIPS/eip-2384.
It specifies the following :
For the purposes of calc_difficulty, simply replace the use of block.number, as used in the exponential ice age component, with the formula:
fake_block_number = max(0, block.number - 9_000_000) if block.number >= MUIR_GLACIER_FORK_BLKNUM else block.number
This will delay the ice age by 52 million seconds (approximately 611 days), so the chain would be back at 20 second block times around July 2021. It’s important to note this pushes the ice age 4,000,000 blocks from ~block 8,800,000 NOT from when this EIP is activated in a fork.