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 | 3 |
| 3 | 11 |
| 4 | 27 |
| 5 | 91 |
| 6 | 347 |
| 7 | 859 |
| 8 | 2907 |
| 9 | 11099 |
| 10 | 43867 |
| 11 | 109403 |
| 12 | 371547 |
| 13 | 1420123 |
| 14 | 5614427 |
| 15 | 22391643 |
| 16 | 55946075 |
| 17 | 190163803 |
| 18 | 727034715 |
| 19 | 2874518363 |
| 20 | 11464452955 |
| 21 | 45824191323 |
| 22 | 114543668059 |
| 23 | 389421575003 |