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 | 7 |
| 3 | 31 |
| 4 | 100 |
| 5 | 364 |
| 6 | 1152 |
| 7 | 3864 |
| 8 | 12102 |
| 9 | 37358 |
| 10 | 113618 |
| 11 | 337562 |
| 12 | 990798 |
| 13 | 2857926 |
| 14 | 8144334 |
| 15 | 22902470 |
| 16 | 63660695 |
| 17 | 175026047 |
| 18 | 476242001 |
| 19 | 1283435153 |
| 20 | 3427047146 |
| 21 | 9072455146 |
| 22 | 23820491998 |
| 23 | 62057045134 |
| 24 | 160471504373 |
| 25 | 412022656517 |
| 26 | 1050740365571 |
| 27 | 2662223436203 |