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 | 3 |
| 4 | 6 |
| 5 | 15 |
| 6 | 46 |
| 7 | 151 |
| 8 | 570 |
| 9 | 2376 |
| 10 | 10961 |
| 11 | 54941 |
| 12 | 297220 |
| 13 | 1720725 |
| 14 | 10602541 |
| 15 | 69176095 |
| 16 | 475881437 |
| 17 | 3439093081 |
| 18 | 26026621617 |
| 19 | 205694058211 |
| 20 | 1693554793730 |
| 21 | 14494778231067 |
| 22 | 128711956613875 |
| 23 | 1183763037547762 |
| 24 | 11258075170582653 |
| 25 | 110558809039675629 |
| 26 | 1119649516271861536 |