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 | 5 |
| 2 | 31 |
| 3 | 172 |
| 4 | 926 |
| 5 | 5078 |
| 6 | 27861 |
| 7 | 152260 |
| 8 | 832207 |
| 9 | 4550810 |
| 10 | 24881731 |
| 11 | 136029644 |
| 12 | 743697760 |
| 13 | 4065948624 |
| 14 | 22229220072 |
| 15 | 121530709245 |
| 16 | 664428372582 |
| 17 | 3632538661095 |
| 18 | 19859679158791 |
| 19 | 108576093277449 |
| 20 | 593603153333233 |