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) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 6 |
| 4 | 17 |
| 5 | 50 |
| 6 | 154 |
| 7 | 490 |
| 8 | 1608 |
| 9 | 5402 |
| 10 | 18475 |
| 11 | 64130 |
| 12 | 225346 |
| 13 | 800046 |
| 14 | 2865471 |
| 15 | 10341168 |
| 16 | 37567524 |
| 17 | 137270954 |
| 18 | 504174183 |
| 19 | 1860277042 |
| 20 | 6892326441 |
| 21 | 25631327354 |
| 22 | 95640861987 |
| 23 | 357975249026 |
| 24 | 1343650153462 |
| 25 | 5056424257510 |
| 26 | 19073789728773 |
| 27 | 72108867616596 |