Problems & Puzzles: Puzzles
Puzzle 110. Dropping-Digits Primes (by Patrick De Geest)
Here you are asked to find the least prime such that it remains prime after all the occurrences of each digit "d" are dropped at the same time, for each distinct digit of the original prime.
Original prime: '1210778071' with 5 distinct digits (0, 1, 2, 7 & 8)
dropping all '0's leaves the prime 12177871
No leading zeros are allowed. This means that if a zero occurs in the original prime, at least two distinct digits must precede it.
Here are the least primes found by Patrick for k=2 to 7:
Can you complete the table