This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 11 |
| 5 | 23 |
| 6 | 72 |
| 7 | 201 |
| 8 | 597 |
| 9 | 1717 |
| 10 | 5183 |
| 11 | 15479 |
| 12 | 46260 |
| 13 | 138928 |
| 14 | 417427 |
| 15 | 1255369 |
| 16 | 3777004 |
| 17 | 11372190 |
| 18 | 34247960 |
| 19 | 103164581 |
| 20 | 310821235 |
| 21 | 936579808 |
| 22 | 2822417917 |
| 23 | 8506019597 |
| 24 | 25636254701 |
| 25 | 77267796877 |
| 26 | 232891865309 |
| 27 | 701970354408 |