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 | 4 |
| 2 | 10 |
| 3 | 29 |
| 4 | 97 |
| 5 | 366 |
| 6 | 1534 |
| 7 | 7050 |
| 8 | 35166 |
| 9 | 188788 |
| 10 | 1082913 |
| 11 | 6592698 |
| 12 | 42315731 |
| 13 | 284431573 |
| 14 | 1988554321 |
| 15 | 14365186163 |
| 16 | 106571030511 |
| 17 | 807548257486 |
| 18 | 6221612919342 |
| 19 | 48551842571129 |
| 20 | 382621726260959 |
| 21 | 3037888284516885 |