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 | 2 |
| 3 | 3 |
| 4 | 7 |
| 5 | 13 |
| 6 | 35 |
| 7 | 88 |
| 8 | 303 |
| 9 | 1119 |
| 10 | 5479 |
| 11 | 32303 |
| 12 | 251135 |
| 13 | 2527712 |
| 14 | 33985853 |
| 15 | 611846940 |
| 16 | 14864650924 |
| 17 | 488222721992 |
| 18 | 21712049275198 |
| 19 | 1308300679611469 |
| 20 | 106897965189674291 |
| 21 | 11852113048215107822 |
| 22 | 1784730721403509209215 |
| 23 | 365323537513403184463273 |