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 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 1 |
| 6 | 3 |
| 7 | 5 |
| 8 | 11 |
| 9 | 22 |
| 10 | 52 |
| 11 | 115 |
| 12 | 273 |
| 13 | 644 |
| 14 | 1573 |
| 15 | 3856 |
| 16 | 9644 |
| 17 | 24279 |
| 18 | 61893 |
| 19 | 158889 |
| 20 | 411428 |
| 21 | 1072028 |
| 22 | 2811609 |
| 23 | 7413463 |
| 24 | 19649241 |
| 25 | 52316944 |
| 26 | 139894857 |
| 27 | 375528799 |
| 28 | 1011716551 |
| 29 | 2734772854 |
| 30 | 7415422577 |
| 31 | 20165386637 |
| 32 | 54986169227 |
| 33 | 150314356310 |
| 34 | 411889718607 |
| 35 | 1131182969207 |
| 36 | 3113152753735 |
| 37 | 8584838194606 |
| 38 | 23718156038153 |
| 39 | 65645270386188 |
| 40 | 181995126904192 |
| 41 | 505374034237230 |
| 42 | 1405493236272560 |
| 43 | 3914493099421124 |
| 44 | 10917513941356709 |
| 45 | 30489195461667752 |
| 46 | 85254349536078343 |
| 47 | 238677545290333506 |
| 48 | 668973049906462186 |
| 49 | 1877097092617714583 |
| 50 | 5272616851131377907 |