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 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 69 |
| 5 | 417 |
| 6 | 2763 |
| 7 | 19609 |
| 8 | 146793 |
| 9 | 1146833 |
| 10 | 9278595 |
| 11 | 77292261 |
| 12 | 659973933 |
| 13 | 5756169681 |
| 14 | 51137399979 |
| 15 | 461691066417 |
| 16 | 4228199347281 |
| 17 | 39216540096993 |
| 18 | 367890444302787 |
| 19 | 3486697883136957 |
| 20 | 33353178454762389 |
| 21 | 321754445379041601 |
| 22 | 3127955713554766923 |
| 23 | 30624486778208481993 |
| 24 | 301790556354721667769 |
| 25 | 2991957347531210976817 |