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 | 0 |
| 1 | 1 |
| 2 | 7 |
| 3 | 76 |
| 4 | 995 |
| 5 | 14433 |
| 6 | 223300 |
| 7 | 3611016 |
| 8 | 60305787 |
| 9 | 1032115315 |
| 10 | 18007816255 |
| 11 | 319110233104 |
| 12 | 5727667197044 |
| 13 | 103913426353324 |
| 14 | 1902498385538520 |
| 15 | 35106179258551632 |
| 16 | 652236828560562987 |
| 17 | 12190651925663309175 |
| 18 | 229059610932456616501 |
| 19 | 4324334144117016053500 |
| 20 | 81983637468108446363755 |