Repdigit (no ontology)

From Compile Worlds

A repdigit, also known as a monomial number, is a polynomial number of order 1, with all digits the same. As such, there are 9 repdigits for each digit-length of number; repdigits occupy 10^1-n of the population of n-digit numbers.

Repdigits up to four digits long are listed as follows:

• 1, 2, 3, 4, 5, 6, 7, 8, 9
• 11, 22, 33, 44, 55, 66, 77, 88, 99
• 111, 222, 333, 444, 555, 666, 777, 888, 999
• 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 9999