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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 109 |
| 6 | 367 |
| 7 | 1245 |
| 8 | 4247 |
| 9 | 14453 |
| 10 | 49167 |
| 11 | 167325 |
| 12 | 569447 |
| 13 | 1937829 |
| 14 | 6594495 |
| 15 | 22441517 |
| 16 | 76369751 |
| 17 | 259890293 |
| 18 | 884421039 |
| 19 | 3009733885 |
| 20 | 10242290119 |
| 21 | 34855077573 |
| 22 | 118613751711 |
| 23 | 403649138125 |
| 24 | 1373640273207 |
| 25 | 4674573594645 |