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 | 3 |
| 2 | 23 |
| 3 | 142 |
| 4 | 838 |
| 5 | 4897 |
| 6 | 28557 |
| 7 | 166460 |
| 8 | 970220 |
| 9 | 5654879 |
| 10 | 32959075 |
| 11 | 192099594 |
| 12 | 1119638514 |
| 13 | 6525731517 |
| 14 | 38034750617 |
| 15 | 221682772216 |
| 16 | 1292061882712 |
| 17 | 7530688524091 |
| 18 | 43892069261871 |
| 19 | 255821727047174 |
| 20 | 1491038293021214 |
| 21 | 8690408031080153 |
| 22 | 50651409893459749 |