This one doesn't really "beat" this, but here is a simple PRNG that you can trivially compute using mental arithmetics proposed by George Marsaglia [1]: 1. Sel

This one doesn't really "beat" this, but here is a simple PRNG that you can trivially compute using mental arithmetics proposed by George Marsaglia [1]: 1. Select an initial random number (seed) between 1 and 58. (This is accomplished by mentally collecting entropy from the environment, e.g. counting a group of objects you don't knew the count of before) 2. Multiply the least significant digit by 6, add the most significant digit to the result, and use the new result as the next seed/state. 3. The second digit of the state is your generated pseudorandom number. 4. Goto 2. Sequence generated by 42: 42 -> 2*6+4=16 -> 6*6+1=37 -> ... 42|16|37|45|34|27|44|28|50|05|03|18|49|58|53|23|20|02|12|13|19|55|35|33|21 2| 6| 7| 5| 4| 7| 4| 8| 0| 5| 3| 8| 9| 8| 3| 3| 0| 2| 2| 3| 9| 5| 5| 3| 1 [1] "Multiply with carry", George Marsaglia (1994): https://groups.google.com/g/sci.math/c/6BIYd0cafQo/m/Ucipn_5T_TMJ https://groups.google.com/g/sci.math/c/6BIYd0cafQo/m/Ucipn_5... Edit: Thanks to lifthrasiir you can try it out your self: (async () => { let x = 42; for (let i = 0; i < 10; ++i) { for (let j = 0; j < 10; ++j) { x = (x / 10) + (x % 10) * 6; (x & 1 ? captureBtnLeftFunc : captureBtnRightFunc)({ preventDefault() {} }); } await new Promise(r => requestAnimationFrame(r)); } })() Edit2: fixed *'s