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 | 4 |
| 2 | 17 |
| 3 | 73 |
| 4 | 313 |
| 5 | 1341 |
| 6 | 5745 |
| 7 | 24613 |
| 8 | 105449 |
| 9 | 451773 |
| 10 | 1935521 |
| 11 | 8292309 |
| 12 | 35526553 |
| 13 | 152205613 |
| 14 | 652091089 |
| 15 | 2793739205 |
| 16 | 11969154121 |
| 17 | 51279178141 |
| 18 | 219694231041 |
| 19 | 941231059125 |
| 20 | 4032495084025 |
| 21 | 17276328107789 |
| 22 | 74016584439345 |
| 23 | 317107590101669 |