0,2

The digits of each term a(n) are a permutation of those of the corresponding term A005151(n). - Chayim Lowen, Jul 16 2015

After a while sequence has period 2.

To get the term after 311322, we say: two 3's, two 1's, two 2's, so 232122.

deldup[ lst_ ] := Module[ {i, s}, s={}; For[ i=1, i<=Length[ lst ], i++, If[ !MemberQ[ s, lst[ [ i ] ] ], AppendTo[ s, lst[ [ i ] ] ] ] ]; s ]; next[ term_ ] := FromDigits[ Flatten[ ({Count[ IntegerDigits[ term ], # ], #}&)/@deldup[ IntegerDigits[ term ] ] ] ]

(Python)

from collections import Counter; s = '1'

for _ in range(25):

print(s, end = ', '); d = Counter(s); s = ''

for k, v in d.items(): s += str(v) + k # Ya-Ping Lu, Jun 06 2025

A variant of A005150, A005151, etc.

Sequence in context: A098155 A098154 A007890 * A005150 A001388 A305660

Adjacent sequences: A063847 A063848 A063849 * A063851 A063852 A063853

base,easy,nonn

N. J. A. Sloane, Aug 25 2001

Corrected and extended by Dean Hickerson, Aug 27 2001

approved