JoshuaZ’s statement implies a peak near 15 for B and outright states 30% of responses to A and C near 7. I would guess that 13 and 17 would be higher than 15 for B and that 7 will still be prominent, and that odd numbers (and, specifically, primes) will be disproportionately represented.
My instinct is that numbers with obvious factors (even numbers and multiples of five especially) will appear less random—and in the range from 1 to 20, that’s all the composites.
JoshuaZ’s statement implies a peak near 15 for B and outright states 30% of responses to A and C near 7. I would guess that 13 and 17 would be higher than 15 for B and that 7 will still be prominent, and that odd numbers (and, specifically, primes) will be disproportionately represented.
I will not edit this comment after posting.
Why primes?
My instinct is that numbers with obvious factors (even numbers and multiples of five especially) will appear less random—and in the range from 1 to 20, that’s all the composites.