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 | 3 |
| 3 | 13 |
| 4 | 58 |
| 5 | 288 |
| 6 | 1512 |
| 7 | 8250 |
| 8 | 46296 |
| 9 | 265491 |
| 10 | 1548976 |
| 11 | 9165156 |
| 12 | 54865737 |
| 13 | 331694167 |
| 14 | 2022232068 |
| 15 | 12419023617 |
| 16 | 76755164643 |
| 17 | 477049187268 |
| 18 | 2979758649996 |
| 19 | 18695276174079 |
| 20 | 117766227611046 |
| 21 | 744527923478730 |
| 22 | 4722464911515423 |
| 23 | 30044091589750350 |