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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 8 |
| 8 | 15 |
| 9 | 26 |
| 10 | 48 |
| 11 | 89 |
| 12 | 163 |
| 13 | 303 |
| 14 | 564 |
| 15 | 1057 |
| 16 | 1985 |
| 17 | 3744 |
| 18 | 7084 |
| 19 | 13443 |
| 20 | 25575 |
| 21 | 48770 |
| 22 | 93206 |
| 23 | 178481 |
| 24 | 342392 |
| 25 | 657930 |
| 26 | 1266204 |
| 27 | 2440322 |
| 28 | 4709393 |
| 29 | 9099506 |
| 30 | 17602324 |
| 31 | 34087042 |
| 32 | 66076419 |
| 33 | 128207978 |
| 34 | 248983611 |
| 35 | 483939977 |
| 36 | 941362695 |
| 37 | 1832519379 |
[0,0,1,1,2,4,8,15,26,48,89,163,303,564,1057,1985, 3744,7084,13443,25575,48770,93206,178481,342392, 657930,1266204,2440322,4709393,9099506,17602324, 34087042,66076419,128207978,248983611,483939977, 941362695,1832519379] |