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 | 6 |
| 3 | 29 |
| 4 | 130 |
| 5 | 562 |
| 6 | 2380 |
| 7 | 9949 |
| 8 | 41226 |
| 9 | 169766 |
| 10 | 695860 |
| 11 | 2842226 |
| 12 | 11576916 |
| 13 | 47050564 |
| 14 | 190876696 |
| 15 | 773201629 |
| 16 | 3128164186 |
| 17 | 12642301534 |
| 18 | 51046844836 |
| 19 | 205954642534 |
| 20 | 830382690556 |
| 21 | 3345997029244 |
| 22 | 13475470680616 |
| 23 | 54244942336114 |
| 24 | 218269673491780 |
| 25 | 877940640368572 |