A045870 Number of times the digits are repeated in A045869.
1, 1, 2, 1, 1, 2, 2, 4, 2, 2, 2, 1, 6, 4, 4, 8, 8, 8, 4, 3, 6, 3, 12, 3, 3, 6, 6, 12, 12, 6, 6, 10, 10, 10, 5, 10, 5, 5, 20, 5, 10, 7, 14, 28, 22, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 22, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 4, 2, 2
Offset: 0
Examples
A045869(1) = 2034, and the divisors of 2034_5 = 269 (a prime) are 1 and 269; in base 5, these are 1 and 2034. Each digit from 0 through 4 appears exactly once, so a(1) = 1. A045869(2) = 2403; 2403_5 = 353 (a prime) has divisors 1 and 353, which in base 5 are 1 and 2403, so each digit in 0..4 appears exactly once, so a(2) = 2. A045869(3) = 2430; 2430_5 = 365 = 5*73, so its divisors are 1, 5, 73, and 365, which in base 5 are 1, 10, 243, and 2430, so each digit in 0..4 appears exactly twice, so a(3) = 2.
Links
- Naohiro Nomoto, In the list of divisors of n, ...
Extensions
Examples edited by Jon E. Schoenfield, Nov 12 2022