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 | 12 |
| 3 | 101 |
| 4 | 760 |
| 5 | 5481 |
| 6 | 38852 |
| 7 | 273421 |
| 8 | 1918320 |
| 9 | 13441361 |
| 10 | 94128892 |
| 11 | 659020341 |
| 12 | 4613496680 |
| 13 | 32295539641 |
| 14 | 226071966132 |
| 15 | 1582513328861 |
| 16 | 11077621999840 |
| 17 | 77543440092321 |
| 18 | 542804338926572 |
| 19 | 3799631147326981 |
| 20 | 26597420355811800 |
| 21 | 186181949464251401 |
| 22 | 1303273667170466212 |