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 | 12 |
| 2 | 94 |
| 3 | 608 |
| 4 | 3525 |
| 5 | 19044 |
| 6 | 97954 |
| 7 | 486000 |
| 8 | 2345930 |
| 9 | 11081880 |
| 10 | 51447036 |
| 11 | 235454848 |
| 12 | 1064832173 |
| 13 | 4767347796 |
| 14 | 21160397050 |
| 15 | 93223960784 |
| 16 | 408037319262 |
| 17 | 1775744775592 |
| 18 | 7688699122724 |
| 19 | 33140226601920 |
| 20 | 142262721338146 |