The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 6 |
| 8 | 10 |
| 9 | 18 |
| 10 | 30 |
| 11 | 50 |
| 12 | 86 |
| 13 | 145 |
| 14 | 245 |
| 15 | 417 |
| 16 | 705 |
| 17 | 1193 |
| 18 | 2024 |
| 19 | 3427 |
| 20 | 5804 |
| 21 | 9836 |
| 22 | 16660 |
| 23 | 28220 |
| 24 | 47811 |
| 25 | 80991 |
| 26 | 137197 |
| 27 | 232423 |
| 28 | 393729 |
| 29 | 666982 |
| 30 | 1129898 |
| 31 | 1914078 |
| 32 | 3242495 |
| 33 | 5492898 |
| 34 | 9305130 |
| 35 | 15763154 |
| 36 | 26703273 |
| 37 | 45236138 |
| 38 | 76631348 |
| 39 | 129815818 |
| 40 | 219911870 |
| 41 | 372537244 |
| 42 | 631089250 |
[1,0,0,1,1,2,4,6,10,18,30,50,86,145,245,417,705, 1193,2024,3427,5804,9836,16660,28220,47811,80991, 137197,232423,393729,666982,1129898,1914078, 3242495,5492898,9305130,15763154,26703273, 45236138,76631348,129815818,219911870,372537244, 631089250] |