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 | 7 |
| 4 | 20 |
| 5 | 63 |
| 6 | 208 |
| 7 | 711 |
| 8 | 2496 |
| 9 | 8944 |
| 10 | 32578 |
| 11 | 120263 |
| 12 | 448938 |
| 13 | 1691776 |
| 14 | 6427130 |
| 15 | 24589043 |
| 16 | 94653498 |
| 17 | 366344216 |
| 18 | 1424750506 |
| 19 | 5565002716 |
| 20 | 21821377624 |
| 21 | 85867522754 |
| 22 | 338974659036 |
| 23 | 1342074448663 |
| 24 | 5327845401606 |
| 25 | 21203102693634 |
| 26 | 84574191671494 |
| 27 | 338060063747476 |