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 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 31 |
| 6 | 86 |
| 7 | 277 |
| 8 | 937 |
| 9 | 3095 |
| 10 | 10275 |
| 11 | 35091 |
| 12 | 121662 |
| 13 | 423286 |
| 14 | 1481648 |
| 15 | 5232315 |
| 16 | 18601843 |
| 17 | 66436069 |
| 18 | 238327939 |
| 19 | 858805613 |
| 20 | 3106856141 |
| 21 | 11277393837 |
| 22 | 41062303214 |
| 23 | 149948280259 |
| 24 | 549027748390 |
| 25 | 2015108865850 |
| 26 | 7412690394406 |
| 27 | 27324968423054 |