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 | 5 |
| 1 | 23 |
| 2 | 103 |
| 3 | 459 |
| 4 | 2043 |
| 5 | 9091 |
| 6 | 40451 |
| 7 | 179987 |
| 8 | 800851 |
| 9 | 3563379 |
| 10 | 15855219 |
| 11 | 70547635 |
| 12 | 313900979 |
| 13 | 1396699187 |
| 14 | 6214598707 |
| 15 | 27651793203 |
| 16 | 123036370227 |
| 17 | 547449067315 |
| 18 | 2435869009715 |
| 19 | 10838374173491 |
| 20 | 48225234713395 |
| 21 | 214577687200563 |
| 22 | 954761218229043 |
| 23 | 4248200247317299 |