At each step, record how many 1's, 2's, etc. have been seen so far in the sequence.
A006920
At each step, record how many 1's, 2's, etc. have been seen so far in the sequence.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =21a(4) =32a(5) =331a(6) =433a(7) =4351a(8) =53621a(9) =647221a(10) =7673221a(11) =8883233a(12) =891132333
External references
- oeis: A006920