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 | 4 |
| 1 | 17 |
| 2 | 75 |
| 3 | 333 |
| 4 | 1481 |
| 5 | 6589 |
| 6 | 29317 |
| 7 | 130445 |
| 8 | 580413 |
| 9 | 2582541 |
| 10 | 11490989 |
| 11 | 51129037 |
| 12 | 227498125 |
| 13 | 1012250573 |
| 14 | 4503998541 |
| 15 | 20040495309 |
| 16 | 89169978317 |
| 17 | 396760903885 |
| 18 | 1765383572173 |
| 19 | 7855056096461 |
| 20 | 34950991530189 |
| 21 | 155514078313677 |
| 22 | 691958296315085 |
| 23 | 3078861341887693 |