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) |
|---|---|
| 3 | 1 |
| 4 | 7 |
| 5 | 39 |
| 6 | 211 |
| 7 | 1168 |
| 8 | 6728 |
| 9 | 40561 |
| 10 | 256297 |
| 11 | 1696707 |
| 12 | 11752973 |
| 13 | 85047284 |
| 14 | 641782220 |
| 15 | 5041634549 |
| 16 | 41160207335 |
| 17 | 348664792199 |
| 18 | 3059885806071 |
| 19 | 27781291314396 |
| 20 | 260599397789924 |
| 21 | 2522492941426381 |
| 22 | 25166308238897929 |
| 23 | 258507111338795491 |
| 24 | 2731176458973448817 |