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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 21 |
| 5 | 68 |
| 6 | 214 |
| 7 | 706 |
| 8 | 2335 |
| 9 | 7968 |
| 10 | 27661 |
| 11 | 98366 |
| 12 | 357212 |
| 13 | 1326169 |
| 14 | 5027377 |
| 15 | 19459252 |
| 16 | 76850284 |
| 17 | 309531069 |
| 18 | 1270740646 |
| 19 | 5314727630 |
| 20 | 22633477157 |
| 21 | 98096319485 |
| 22 | 432490992805 |
| 23 | 1938762984374 |
| 24 | 8832924638252 |
| 25 | 40882143931620 |
| 26 | 192148753444380 |
| 27 | 916747097916418 |