The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 4 |
| 3 | 15 |
| 4 | 35 |
| 5 | 81 |
| 6 | 174 |
| 7 | 364 |
| 8 | 740 |
| 9 | 1459 |
| 10 | 2778 |
| 11 | 5105 |
| 12 | 9069 |
| 13 | 15615 |
| 14 | 26129 |
| 15 | 42600 |
| 16 | 67827 |
| 17 | 105680 |
| 18 | 161425 |
| 19 | 242124 |
| 20 | 357122 |
| 21 | 518634 |
| 22 | 742446 |
| 23 | 1048745 |
| 24 | 1463094 |
| 25 | 2017569 |
| 26 | 2752076 |
| 27 | 3715867 |
| 28 | 4969275 |
| 29 | 6585689 |
| 30 | 8653791 |
| 31 | 11280078 |
| 32 | 14591693 |
| 33 | 18739590 |
[4,4,15,35,81,174,364,740,1459,2778,5105,9069, 15615,26129,42600,67827,105680,161425,242124, 357122,518634,742446,1048745,1463094,2017569, 2752076,3715867,4969275,6585689,8653791,11280078, 14591693,18739590] |