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 | 10 |
| 3 | 19 |
| 4 | 109 |
| 5 | 280 |
| 6 | 1261 |
| 7 | 3781 |
| 8 | 15130 |
| 9 | 49159 |
| 10 | 185329 |
| 11 | 627760 |
| 12 | 2295721 |
| 13 | 7945561 |
| 14 | 28607050 |
| 15 | 100117099 |
| 16 | 357580549 |
| 17 | 1258634440 |
| 18 | 4476859381 |
| 19 | 15804569341 |
| 20 | 56096303770 |
| 21 | 198337427839 |
| 22 | 703204161769 |
| 23 | 2488241012320 |
| 24 | 8817078468241 |
| 25 | 31211247579121 |
| 26 | 110564953793290 |