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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 20 |
| 5 | 49 |
| 6 | 123 |
| 7 | 312 |
| 8 | 824 |
| 9 | 2221 |
| 10 | 6235 |
| 11 | 17904 |
| 12 | 53348 |
| 13 | 162545 |
| 14 | 511747 |
| 15 | 1645776 |
| 16 | 5448600 |
| 17 | 18404189 |
| 18 | 63794611 |
| 19 | 225353368 |
| 20 | 814801812 |
| 21 | 2999022641 |
| 22 | 11274044075 |
| 23 | 43100574472 |
| 24 | 167987074584 |
| 25 | 665229445293 |
| 26 | 2681607587627 |
| 27 | 10973746015456 |