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 | 5 |
| 2 | 27 |
| 3 | 146 |
| 4 | 787 |
| 5 | 4230 |
| 6 | 22686 |
| 7 | 121476 |
| 8 | 649731 |
| 9 | 3472382 |
| 10 | 18546922 |
| 11 | 99023292 |
| 12 | 528535726 |
| 13 | 2820451964 |
| 14 | 15048601308 |
| 15 | 80283276936 |
| 16 | 428271193827 |
| 17 | 2284478396334 |
| 18 | 12185310873138 |
| 19 | 64993897108236 |
| 20 | 346655914156602 |
| 21 | 1848916875734004 |
| 22 | 9861224376230628 |
| 23 | 52594507923308856 |