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 | 1 |
| 3 | 8 |
| 4 | 43 |
| 5 | 295 |
| 6 | 1982 |
| 7 | 14379 |
| 8 | 106464 |
| 9 | 811769 |
| 10 | 6304231 |
| 11 | 49770106 |
| 12 | 398042059 |
| 13 | 3218655532 |
| 14 | 26269422252 |
| 15 | 216121646661 |
| 16 | 1790428656802 |
| 17 | 14922986525284 |
| 18 | 125050910828179 |
| 19 | 1052916751167676 |
| 20 | 8903502888220215 |
| 21 | 75579379572985970 |
| 22 | 643818145873489913 |