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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 18 |
| 5 | 79 |
| 6 | 408 |
| 7 | 2469 |
| 8 | 17314 |
| 9 | 138555 |
| 10 | 1247052 |
| 11 | 12470593 |
| 12 | 137176614 |
| 13 | 1646119479 |
| 14 | 21399553360 |
| 15 | 299593747197 |
| 16 | 4493906208138 |
| 17 | 71902499330419 |
| 18 | 1222342488617364 |
| 19 | 22002164795112825 |
| 20 | 418041131107143982 |
| 21 | 8360822622142879983 |
| 22 | 175577275065000480024 |
| 23 | 3862700051430010560949 |