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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 21 |
| 6 | 161 |
| 7 | 911 |
| 8 | 3473 |
| 9 | 48329 |
| 10 | 406241 |
| 11 | 2150171 |
| 12 | 44216921 |
| 13 | 491897693 |
| 14 | 3327845249 |
| 15 | 90934644711 |
| 16 | 1257256962081 |
| 17 | 10352273016081 |
| 18 | 353351881109313 |
| 19 | 5836715156967219 |
| 20 | 56621346170765481 |
| 21 | 2319460179075419941 |
| 22 | 44545835926727113441 |
| 23 | 497433851743810193983 |
| 24 | 23782590451590763744689 |