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 | 11 |
| 3 | 69 |
| 4 | 354 |
| 5 | 1650 |
| 6 | 7293 |
| 7 | 31213 |
| 8 | 130832 |
| 9 | 540702 |
| 10 | 2212550 |
| 11 | 8989090 |
| 12 | 36327810 |
| 13 | 146228940 |
| 14 | 586823265 |
| 15 | 2349424125 |
| 16 | 9389012160 |
| 17 | 37467344310 |
| 18 | 149345215290 |
| 19 | 594753416790 |
| 20 | 2366845396500 |
| 21 | 9413555798556 |
| 22 | 37423053793026 |
| 23 | 148719333293394 |
| 24 | 590842248405024 |
| 25 | 2346813893147500 |