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 | 0 |
| 1 | 1 |
| 2 | 7 |
| 3 | 37 |
| 4 | 177 |
| 5 | 807 |
| 6 | 3579 |
| 7 | 15591 |
| 8 | 67071 |
| 9 | 285861 |
| 10 | 1209641 |
| 11 | 5089517 |
| 12 | 21314453 |
| 13 | 88918353 |
| 14 | 369734553 |
| 15 | 1533115953 |
| 16 | 6341759073 |
| 17 | 26177411943 |
| 18 | 107853629643 |
| 19 | 443633635743 |
| 20 | 1822098923943 |
| 21 | 7473806605563 |
| 22 | 30618895206483 |
| 23 | 125303348573883 |
| 24 | 512274592771083 |
| 25 | 2092407173242983 |
| 26 | 8539348101568335 |