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 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 13 |
| 5 | 33 |
| 6 | 112 |
| 7 | 286 |
| 8 | 769 |
| 9 | 2288 |
| 10 | 6695 |
| 11 | 18745 |
| 12 | 54654 |
| 13 | 160888 |
| 14 | 467402 |
| 15 | 1362378 |
| 16 | 4016517 |
| 17 | 11807966 |
| 18 | 34708018 |
| 19 | 102451390 |
| 20 | 302870005 |
| 21 | 895207191 |
| 22 | 2650590597 |
| 23 | 7859253320 |
| 24 | 23316653154 |
| 25 | 69231883374 |
| 26 | 205773157904 |
| 27 | 612021943421 |
| 28 | 1821435719846 |
| 29 | 5424528040529 |
| 30 | 16165017705176 |