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 | 5 |
| 3 | 17 |
| 4 | 69 |
| 5 | 339 |
| 6 | 1677 |
| 7 | 9321 |
| 8 | 55137 |
| 9 | 343659 |
| 10 | 2285289 |
| 11 | 15910857 |
| 12 | 116120781 |
| 13 | 886308147 |
| 14 | 7033465989 |
| 15 | 58008074409 |
| 16 | 495792941337 |
| 17 | 4381170220251 |
| 18 | 39980186877537 |
| 19 | 376025841184329 |
| 20 | 3640077999981189 |
| 21 | 36224841818288547 |
| 22 | 370112212444620861 |
| 23 | 3878334404076375657 |