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 | 1 |
| 2 | 4 |
| 3 | 15 |
| 4 | 59 |
| 5 | 230 |
| 6 | 901 |
| 7 | 3522 |
| 8 | 13773 |
| 9 | 53847 |
| 10 | 210527 |
| 11 | 823087 |
| 12 | 3218002 |
| 13 | 12581319 |
| 14 | 49188823 |
| 15 | 192312112 |
| 16 | 751877137 |
| 17 | 2939592383 |
| 18 | 11492839729 |
| 19 | 44933224559 |
| 20 | 175674134309 |
| 21 | 686828104551 |
| 22 | 2685272063984 |
| 23 | 10498530869151 |
| 24 | 41045803846015 |
| 25 | 160475597429847 |