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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 16 |
| 6 | 61 |
| 7 | 271 |
| 8 | 1372 |
| 9 | 7795 |
| 10 | 49093 |
| 11 | 339386 |
| 12 | 2554596 |
| 13 | 20794982 |
| 14 | 182010945 |
| 15 | 1704439030 |
| 16 | 17003262470 |
| 17 | 180011279335 |
| 18 | 2015683264820 |
| 19 | 23801055350435 |
| 20 | 295563725628564 |
| 21 | 3850618520827590 |
| 22 | 52514066450469255 |
| 23 | 748191494586458700 |
| 24 | 11115833059268126770 |