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 | 1 |
| 2 | 3 |
| 3 | 5 |
| 4 | 13 |
| 5 | 33 |
| 6 | 85 |
| 7 | 221 |
| 8 | 597 |
| 9 | 1655 |
| 10 | 4593 |
| 11 | 12775 |
| 12 | 35629 |
| 13 | 99651 |
| 14 | 279501 |
| 15 | 786071 |
| 16 | 2252509 |
| 17 | 6460433 |
| 18 | 18542169 |
| 19 | 53260481 |
| 20 | 153115765 |
| 21 | 440572993 |
| 22 | 1268830877 |
| 23 | 3657435745 |
| 24 | 10551936125 |
| 25 | 30469329025 |
| 26 | 88056216233 |
| 27 | 256521698097 |