@rhino.fi/client-js/src/lib/stark/ledger/getBits.js

/*
Returns 2 least significant bit blocks of 31 bits each
*/

module.exports = address => {
  // address to bits
  const hBits = BigInt(address).toString(2)
  // last and second last 31 bit blocks
  const first31Bits = parseInt(hBits.slice(-31), 2)
  const second31Bits = parseInt(hBits.slice(-62, -31), 2)

  return [first31Bits, second31Bits]
}