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 | 9409 |
| 3 | 332929 |
| 4 | 3690241 |
| 5 | 23049601 |
| 6 | 101626561 |
| 7 | 354079489 |
| 8 | 1040514049 |
| 9 | 2687489281 |
| 10 | 6272798401 |
| 11 | 13493377921 |
| 12 | 27138279169 |
| 13 | 51591216769 |
| 14 | 93489789121 |
| 15 | 162571046401 |
| 16 | 272735662081 |
| 17 | 443365544449 |
| 18 | 700932305089 |
| 19 | 1080936581761 |
| 20 | 1630220793601 |
| 21 | 2409700487041 |