OFFSET
0,1
COMMENTS
a(n) does not depend on the order of digits of n, a property inherited from A047842. - M. F. Hasler, Jan 11 2024
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
FORMULA
From M. F. Hasler, Jan 11 2024: (Start)
a(n) = a(A328447(n)) = a(m) for all n and all m having the same digits as n, considering their respective multiplicity.
EXAMPLE
a(10) = A047842(1011) = 1031;
a(11) = A047842(21) = 1112;
a(12) = A047842(1112) = 3112;
a(100) = A047842(2011) = 102112;
a(101) = A047842(1021) = 102112;
a(102) = A047842(101112) = 104112.
For n = 20231231, digits of the date 2023-12-31, a(n) = 10213223 = A047842(n) because this is a fixed point of A047842. Since the order of the digits of n does not matter and there are no leading zeros, this holds also for the numbers resulting from notation dd.mm.yyyy or mm/dd/yyyy. - M. F. Hasler, Jan 11 2024
PROG
(Haskell)
a235775 = a047842 . a047842
(Python)
def A235775(n):
s = str(n)
s = ''.join(str(s.count(d))+d for d in sorted(set(s)))
return int(''.join(str(s.count(d))+d for d in sorted(set(s)))) # Chai Wah Wu, Feb 12 2023
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Jan 15 2014
STATUS
approved