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 | 2 |
| 3 | 7 |
| 4 | 23 |
| 5 | 72 |
| 6 | 227 |
| 7 | 725 |
| 8 | 2332 |
| 9 | 7537 |
| 10 | 24465 |
| 11 | 79720 |
| 12 | 260633 |
| 13 | 854539 |
| 14 | 2808768 |
| 15 | 9252315 |
| 16 | 30536925 |
| 17 | 100959558 |
| 18 | 334301159 |
| 19 | 1108483583 |
| 20 | 3680134756 |
| 21 | 12231824111 |
| 22 | 40697552035 |
| 23 | 135536687436 |
| 24 | 451776392011 |
| 25 | 1507088458381 |
| 26 | 5031254413136 |
| 27 | 16807872970501 |
| 28 | 56185887793379 |