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 | 20 |
| 5 | 51 |
| 6 | 130 |
| 7 | 331 |
| 8 | 843 |
| 9 | 2147 |
| 10 | 5468 |
| 11 | 13926 |
| 12 | 35467 |
| 13 | 90328 |
| 14 | 230049 |
| 15 | 585893 |
| 16 | 1492163 |
| 17 | 3800268 |
| 18 | 9678592 |
| 19 | 24649615 |
| 20 | 62778090 |
| 21 | 159884387 |
| 22 | 407196479 |
| 23 | 1037055435 |
| 24 | 2641191736 |
| 25 | 6726635386 |
| 26 | 17131517943 |
| 27 | 43630863008 |
| 28 | 111119879345 |
| 29 | 283002139641 |
| 30 | 720755021635 |