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 | 21 |
| 3 | 231 |
| 4 | 1540 |
| 5 | 7260 |
| 6 | 26796 |
| 7 | 82621 |
| 8 | 222111 |
| 9 | 536130 |
| 10 | 1186570 |
| 11 | 2445366 |
| 12 | 4747821 |
| 13 | 8763391 |
| 14 | 15487395 |
| 15 | 26357430 |
| 16 | 43398586 |
| 17 | 69401871 |
| 18 | 108140571 |
| 19 | 164629585 |
| 20 | 245433090 |
| 21 | 359026206 |
| 22 | 516216646 |
| 23 | 730632651 |
| 24 | 1019283825 |
| 25 | 1403201800 |
| 26 | 1908167976 |
| 27 | 2565535896 |
| 28 | 3413156131 |