The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 11 |
| 3 | 21 |
| 4 | 121 |
| 5 | 1121 |
| 6 | 21121 |
| 7 | 121121 |
| 8 | 2121 |
| 9 | 221 |
| 10 | 2211 |
| 11 | 2221 |
| 12 | 3211 |
| 13 | 13211 |
| 14 | 113211 |
| 15 | 2113211 |
| 16 | 12113211 |
| 17 | 112113211 |
| 18 | 2112113211 |
| 19 | 221113211 |
| 20 | 223113211 |
| 21 | 2213113211 |
| 22 | 22113113211 |
| 23 | 2221131211 |
| 24 | 3221131211 |
| 25 | 13221131211 |
| 26 | 113221131211 |
| 27 | 2113221131211 |
| 28 | 12113221131211 |
[1,11,21,121,1121,21121,121121,2121,221,2211,2221, 3211,13211,113211,2113211,12113211,112113211, 2112113211,221113211,223113211,2213113211, 22113113211,2221131211,3221131211,13221131211, 113221131211,2113221131211,12113221131211] |