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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 18 |
| 4 | 137 |
| 5 | 650 |
| 6 | 2350 |
| 7 | 6860 |
| 8 | 17609 |
| 9 | 39870 |
| 10 | 83976 |
| 11 | 162382 |
| 12 | 301070 |
| 13 | 522886 |
| 14 | 885284 |
| 15 | 1424468 |
| 16 | 2254537 |
| 17 | 3419448 |
| 18 | 5143987 |
| 19 | 7448874 |
| 20 | 10750712 |
| 21 | 15015872 |
| 22 | 20948610 |
| 23 | 28373444 |
| 24 | 38539022 |
| 25 | 50863150 |
| 26 | 67454492 |
| 27 | 87209316 |
| 28 | 113326308 |
| 29 | 143748766 |
| 30 | 183759900 |
| 31 | 229271536 |