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 | 2 |
| 2 | 3 |
| 3 | 8 |
| 4 | 19 |
| 5 | 46 |
| 6 | 111 |
| 7 | 268 |
| 8 | 647 |
| 9 | 1562 |
| 10 | 3771 |
| 11 | 9104 |
| 12 | 21979 |
| 13 | 53062 |
| 14 | 128103 |
| 15 | 309268 |
| 16 | 746639 |
| 17 | 1802546 |
| 18 | 4351731 |
| 19 | 10506008 |
| 20 | 25363747 |
| 21 | 61233502 |
| 22 | 147830751 |
| 23 | 356895004 |
| 24 | 861620759 |
| 25 | 2080136522 |
| 26 | 5021893803 |
| 27 | 12123924128 |
| 28 | 29269742059 |
| 29 | 70663408246 |
| 30 | 170596558551 |
| 31 | 411856525348 |