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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 30 |
| 4 | 90 |
| 5 | 269 |
| 6 | 788 |
| 7 | 2249 |
| 8 | 6340 |
| 9 | 17526 |
| 10 | 47911 |
| 11 | 129639 |
| 12 | 348251 |
| 13 | 929714 |
| 14 | 2469499 |
| 15 | 6532869 |
| 16 | 17219031 |
| 17 | 45246630 |
| 18 | 118572805 |
| 19 | 309998131 |
| 20 | 808746993 |
| 21 | 2105893899 |
| 22 | 5474080107 |
| 23 | 14207001052 |
| 24 | 36818679828 |
| 25 | 95292132897 |
| 26 | 246327403310 |