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 | 4 |
| 4 | 13 |
| 5 | 36 |
| 6 | 106 |
| 7 | 323 |
| 8 | 981 |
| 9 | 2992 |
| 10 | 9196 |
| 11 | 28392 |
| 12 | 87946 |
| 13 | 273287 |
| 14 | 851579 |
| 15 | 2659764 |
| 16 | 8324357 |
| 17 | 26100560 |
| 18 | 81969496 |
| 19 | 257800532 |
| 20 | 811862268 |
| 21 | 2559731360 |
| 22 | 8079294664 |
| 23 | 25525787344 |
| 24 | 80719066698 |
| 25 | 255466082911 |
| 26 | 809138591431 |
| 27 | 2564605664428 |
| 28 | 8134003910311 |
| 29 | 25813957574292 |