The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 28 |
| 3 | 76 |
| 4 | 204 |
| 5 | 580 |
| 6 | 1556 |
| 7 | 4180 |
| 8 | 11204 |
| 9 | 29724 |
| 10 | 79276 |
| 11 | 212076 |
| 12 | 565692 |
| 13 | 1509332 |
| 14 | 4026028 |
| 15 | 10740796 |
| 16 | 28646804 |
| 17 | 76396620 |
| 18 | 203728972 |
| 19 | 543283204 |
| 20 | 1448779164 |
| 21 | 3863345612 |
| 22 | 10302538780 |
| 23 | 27473690092 |
| 24 | 73263231116 |
| 25 | 195369181668 |
| 26 | 520985280228 |
| 27 | 1389296277316 |
| 28 | 3704793953044 |
[1,8,28,76,204,580,1556,4180,11204,29724,79276, 212076,565692,1509332,4026028,10740796,28646804, 76396620,203728972,543283204,1448779164, 3863345612,10302538780,27473690092,73263231116, 195369181668,520985280228,1389296277316, 3704793953044] |