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 | 6 |
| 2 | 27 |
| 3 | 140 |
| 4 | 651 |
| 5 | 2772 |
| 6 | 11354 |
| 7 | 44640 |
| 8 | 169371 |
| 9 | 624742 |
| 10 | 2248575 |
| 11 | 7922124 |
| 12 | 27397937 |
| 13 | 93214632 |
| 14 | 312559200 |
| 15 | 1034507696 |
| 16 | 3384194616 |
| 17 | 10954244952 |
| 18 | 35118346760 |
| 19 | 111602517096 |
| 20 | 351819819414 |
| 21 | 1100912299156 |
| 22 | 3421515852834 |
| 23 | 10566654790176 |
| 24 | 32441857824859 |
| 25 | 99060134392422 |