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 | 3 |
| 1 | 25 |
| 2 | 130 |
| 3 | 546 |
| 4 | 2037 |
| 5 | 7071 |
| 6 | 23436 |
| 7 | 75328 |
| 8 | 237127 |
| 9 | 735813 |
| 10 | 2260518 |
| 11 | 6896046 |
| 12 | 20933673 |
| 13 | 63325051 |
| 14 | 191088976 |
| 15 | 575625900 |
| 16 | 1731858075 |
| 17 | 5206059585 |
| 18 | 15640198410 |
| 19 | 46966732090 |
| 20 | 140996664733 |
| 21 | 423191320215 |
| 22 | 1269993390420 |