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 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 44 |
| 5 | 266 |
| 6 | 1599 |
| 7 | 9597 |
| 8 | 57586 |
| 9 | 345520 |
| 10 | 2073125 |
| 11 | 12438755 |
| 12 | 74632536 |
| 13 | 447795222 |
| 14 | 2686771339 |
| 15 | 16120628041 |
| 16 | 96723768254 |
| 17 | 580342609532 |
| 18 | 3482055657201 |
| 19 | 20892333943215 |
| 20 | 125354003659300 |
| 21 | 752124021955810 |
| 22 | 4512744131734871 |
| 23 | 27076464790409237 |
| 24 | 162458788742455434 |
| 25 | 974752732454732616 |