A063850 Say what you see in previous term, reporting total number for each digit encountered.

1, 11, 21, 1211, 3112, 132112, 311322, 232122, 421311, 14123113, 41141223, 24312213, 32142321, 23322114, 32232114, 23322114, 32232114, 23322114, 32232114, 23322114, 32232114, 23322114, 32232114, 23322114, 32232114

Offset: 0

Author

N. J. A. Sloane, Aug 25 2001

Keywords

• base
• easy
• nonn

Comments

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

Examples

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

Crossrefs

A variant of A005150, A005151, etc.

Programs

Mathematica

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

Formula

After a while sequence has period 2.

Extensions

Corrected and extended by Dean Hickerson, Aug 27 2001