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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 10 |
| 6 | 38 |
| 7 | 101 |
| 8 | 353 |
| 9 | 1070 |
| 10 | 3659 |
| 11 | 11843 |
| 12 | 40505 |
| 13 | 135873 |
| 14 | 468104 |
| 15 | 1604375 |
| 16 | 5576315 |
| 17 | 19386656 |
| 18 | 67950717 |
| 19 | 238676813 |
| 20 | 842797959 |
| 21 | 2983745508 |
| 22 | 10603445402 |
| 23 | 37777263153 |
| 24 | 134985354179 |
| 25 | 483438728094 |
| 26 | 1735527037388 |
| 27 | 6243193190117 |
| 28 | 22503637842423 |