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 | 495 |
| 1 | 11583 |
| 2 | 135135 |
| 3 | 1061775 |
| 4 | 6370650 |
| 5 | 31286970 |
| 6 | 131405274 |
| 7 | 486370170 |
| 8 | 1621233900 |
| 9 | 4946841900 |
| 10 | 13992495660 |
| 11 | 37058912748 |
| 12 | 92647281870 |
| 13 | 220089696750 |
| 14 | 499568676750 |
| 15 | 1088533853550 |
| 16 | 2285921092455 |
| 17 | 4642276728375 |
| 18 | 9143878404375 |
| 19 | 17513561154375 |
| 20 | 32691980821500 |
| 21 | 59592810754620 |