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 | 3 |
| 2 | 7 |
| 3 | 19 |
| 4 | 53 |
| 5 | 149 |
| 6 | 419 |
| 7 | 1191 |
| 8 | 3403 |
| 9 | 9755 |
| 10 | 28077 |
| 11 | 81097 |
| 12 | 234861 |
| 13 | 681697 |
| 14 | 1982723 |
| 15 | 5777375 |
| 16 | 16861521 |
| 17 | 49281525 |
| 18 | 144222987 |
| 19 | 422566835 |
| 20 | 1239423303 |
| 21 | 3638872529 |
| 22 | 10693065215 |
| 23 | 31448140529 |
| 24 | 92558787745 |
| 25 | 272612601065 |
| 26 | 803448576111 |