The Rien Number
Perl, 44 42 41 33 31 bytes
Yaaay, first post ever !
Thanks to primo for the 2 bytes save.
print 1,sort"@{[2..<>]}"=~/\d/g
As others did, removing 1 and prepending it manually does the work.
Try it online
Pyth, 8
+1SjktSQ
Makes a list [1, .. , input]
then removes the leading one, joins and sorts, then prepends a 1.
Test Suite
Japt, 14 12 bytes
1+2o°U ¬¬n ¬
Try it online!
How it works
1+2o°U ¬¬n ¬ // Implicit: U = input integer
2o°U // Generate the range of integers from 2 to U, inclusive.
¬¬ // Join, then split into chars.
n // Sort.
1+ ¬ // Join again, and add a 1 to the beginning.
// Implicit: output last expression