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 | 15 |
| 2 | 110 |
| 3 | 545 |
| 4 | 2120 |
| 5 | 7043 |
| 6 | 20965 |
| 7 | 57560 |
| 8 | 148545 |
| 9 | 365045 |
| 10 | 862224 |
| 11 | 1970905 |
| 12 | 4382820 |
| 13 | 9520315 |
| 14 | 20265665 |
| 15 | 42385132 |
| 16 | 87284120 |
| 17 | 177293730 |
| 18 | 355738710 |
| 19 | 705980760 |
| 20 | 1387213926 |
| 21 | 2701362950 |
| 22 | 5217448800 |
| 23 | 10001654350 |